There sure are a lot of crickets here.
September 9, 2022 6:34 PM   Subscribe

I am sitting on my porch in eastern Massachusetts on a September evening and the crickets are very loud. There are a lot of them. Approximately how many are in a hundred yard radius of where I am?

I have no idea if the answer is 100 crickets or 10,000 crickets. Maybe it's a million crickets. Sure sounds like a million.

A quick google for "cricket population density" seemed to bring up some pages that have nothing to do with the answer to my question.

I am in an older suburban neighborhood with a lot of woods around me, within 100 yards of a lake. The neighborhood is filled with houses with medium-sized lawns and gardens. The current temperature at 9:25 PM is 63 degrees.

This being Ask Metafilter, surely one of you knows how many crickets per square foot there are in my part of the world. Please show your work.

I promise there is no amount of crickets that will freak me out.
posted by bondcliff to Science & Nature (39 answers total) 8 users marked this as a favorite
 
Response by poster: And just to be clear: I am looking for a rough estimate. I don't need you to actually count the crickets.
posted by bondcliff at 6:38 PM on September 9 [11 favorites]


We can calculate this by putting upper and lower bounds on the problem, which we can improve upon as we come up with more accurate cricket-packing models. To aid in this I've made a few basic estimates to get us started.

Since you report hearing multiple crickets in close proximity, the lower bound is at least two.

For an upper bound, let us assume a cubic cricket of volume 1cm3. I think that volume is a little generous for your average cricket - turns out searches for 'cricket volume' don't get you far either, so that's hard to say - but I'm also reasonably sure crickets don't tesselate, so there's a trade-off here.

I assume you would notice if, during your evening sojourns, you were wading through a 1cm (0.4in) sea of crickets, so I think it's reasonable to state that the upper bound is less than a 1cm depth of crickets over the 100yd radius circle, which I calculate to require approximately 265,638,696.8 crickets.

This does not allow for trees holding up a carpet of perfectly packed 1cm3 crickets clear of the ground (so you would not be wading through them), but if that were happening I feel sure you would have reported a sense of impending doom.
posted by How much is that froggie in the window at 6:55 PM on September 9 [32 favorites]


Response by poster: Nope, still not freaked out.
posted by bondcliff at 6:59 PM on September 9 [4 favorites]


I am just here to say that I, also in eastern Massachusetts on a September evening in an older suburban area near water, am willing to put some money down on "north of a million."

(Also, there is definitely a number of crickets that would freak me out. That number changes based on variables like "crickets heard" (a lot), "crickets seen" (...five? six?), "cricket on my leg" (one, just one, get it OFF!))
posted by invincible summer at 7:28 PM on September 9 [7 favorites]


Best answer: 2500
posted by bendy at 7:28 PM on September 9 [5 favorites]


Listening right now in Salem, next to a cemetery, I’m gonna guess 10k.
posted by bowbeacon at 7:35 PM on September 9 [1 favorite]


Do you have a decibel meter on your phone? If so, a little research into the volume of an individual cricket's chirp and some acoustics theory might help you develop some assumptions resulting in a decent estimate.
posted by carmicha at 7:38 PM on September 9 [7 favorites]


But I think we can surmise that the cricket density increases with distance from you, since you're probably kinda scary. To a cricket.
posted by carmicha at 7:41 PM on September 9 [6 favorites]


I think we have to start by assuming a spherical cricket otherwise we can’t be considered to be being truly scientific, and I suspect that How much is that froggie in the window was not considering the packing factor in their estimate of the upper bound.

Nevertheless, I suspect a Fermi estimate would not expect a seamless carpet of crickets as a reasonable upper bound. On the other hand if you assumed 10 a ten cricket per square meter average (they may be closer in some places, but there are also many places where they cannot be, say inside tree trunks) you would have 314,159 within a hundred meter radius.
posted by Quinbus Flestrin at 8:22 PM on September 9 [5 favorites]


Let's see, 100 yard radius so area is (pi x r^2) so 10000 x 3.1415... so about 31416 square yards. Dismissing the vertical for the moment and assuming a couple or three crickets per square yard and you get about 6000 to 9000 crickets. Going vertical up in the trees and such maybe dozens to hundreds of crickets per square yard. Let's say 100 is a good maximum guess taking into account the difference between lawns and houses and forests and trees as a bit of an average. So 3,141,600 crickets. I would probably half that because 100 per square yard even including the vertical tree space sounds a bit on the large side. And I'm not really sure crickets get that high up into trees, they can't fly can they? So probably really only about 10,000 or so give or take an order of magnitude.

Oops, missed a magnitude in there, 31416 x 2 is roughly 60,000 and x 3 is roughly 90,000 so that should end up being about 100,000 as the good estimate. (teach me to use commas in big numbers)
posted by zengargoyle at 8:22 PM on September 9 [4 favorites]


low thousands, not millions?

THIS paper points out that
a) crickets are territorial (!) (...which I did not realize - this must limit their density)
and
b) in their (Texas) measurements, they describe "low density" as ~0.025 crickets sq meter; and "high density" as 0.115 crickets per sq. meter

So - back of the envelope:
100yd radius = 90 meters.
pi r^2 = 3.14 x 8100 = 25,000 square meters.

At 0.025 crickets /sq meter, that's roughly ~625 crickets
at 0.115/sq meter that's roughly ~2900 crickets.

I couldn't guess how Texas- and Massachusetts cricket densities vary.
posted by AsYouKnow Bob at 8:42 PM on September 9 [31 favorites]


Now if you want to be particular.... all spherical cow like...

Assume that crickets don't like people and houses that much if they can avoid it so your circle is denser in crickets at the outer edge than it is in the middle where you are. Lump in your neighbors in to that bit. Then assume that at the limit of the 100 yards there may be 10 or 20 crickets per square yard while near you there might be only one or two in your square yard. So assume the density of crickets falls off in ten yard increments by 10% and so a summation. Calculate the 100 yard circle density at the 100 yard mark, then calculate the 100 yard density at the 90 yard mark and subtract. This is the number of crickets in that 10 yard band on the edge. Reduce the density by 10% and do the same for a 90 yard circle minus the 80 yard circle to get the number of crickets in that 10 yard ring from 90 to 80 yards away from you. Repeat until you end up with the final 10 yard circle around you. Then add up the partial sums.

I'll leave doing the calculus to someone else because I'm old and rusty. Should be pretty easy to turn this into a (radius, density, rate of change) thing and plug in numbers. Then you just have to build a 1 square yard box and go out and sneakily sample the population at various distances to get good numbers to put in.
posted by zengargoyle at 8:47 PM on September 9 [2 favorites]


Wow AsYouKnow Bob, no clue that density would be that low.
posted by zengargoyle at 8:50 PM on September 9 [1 favorite]



$ raku -e '
my $t=0;
my $d=0.05;
for 100, 90 ... 10 -> $r {
 my $rr=($r**2*pi*$d)-(($r-10)**2*pi*$d);
 say "$r $rr";
 $t+=$rr;
 $d*=0.1;
};
say "total $t";
' 

100 298.45130209103036
90 26.703537555513236
80 2.356194490192345
70 0.20420352248333662
60 0.017278759594743856
50 0.0014137166941154073
40 0.00010995574287564274
30 7.853981633974482e-06
20 4.7123889803846896e-07
10 1.5707963267948965e-08
total 327.7340484321794
Not that many crickets at all! Loud bastards. That's middle density (between .025 and .100 roughly, 0.05 sounds reasonable. And dropping by 10% every 10 yards closer to you. And ignoring the whole yard vs meter thing altogether. QED

(and yes that was originally a one-line program)
posted by zengargoyle at 9:10 PM on September 9 [2 favorites]


If we go for maximum density of 0.115 and no drop of due to closeness....

100 686.4379948093701
90 614.1813637768041
80 541.9247327442395
70 469.6681017116741
60 397.4114706791089
50 325.15483964654356
40 252.8982086139784
30 180.64157758141312
20 108.38494654884788
10 36.128315516282626
total 3612.831551628263

posted by zengargoyle at 9:14 PM on September 9


Response by poster: I don't think we have to consider them decreasing as they get closer. I'm on a screened-in porch and not making much noise or moving much. Just outside the screen are some bushes and then my lawn. Ten feet to my south is a wooded lot, across the street is woods and then the lake.

I'm appreciating the well thought-out answers as well as the snarky ones. Keep 'em coming.
posted by bondcliff at 9:15 PM on September 9


Ah, fuck me. I should have multiplied density by 0.9 not 0.1, I was giving a 90% drop in density per 10 yards. See what you get kiddies for bashing out one-liners....

The 3,613 is the spherical cow number based on Texas high density blah blah.
The 10% drop comes in at 2,754. The drop off if any should probably be inverse radius squared or some other fancier curve if there even is need for one.
posted by zengargoyle at 9:27 PM on September 9


Oh, simple and precise... if we go metric and such 100 yards is 91.44 meters and it's a simple...
$ raku -e 'say 91.44**2*pi*0.115'
3020.787307387643
Crickets......

A 100 yard radius circle is 26267.715716414285 square meters if you want to futz around, just multiply by density/meter**2.
posted by zengargoyle at 9:36 PM on September 9 [1 favorite]


Wow AsYouKnow Bob, no clue that density would be that low.
posted by zengargoyle at 11:50 PM


Yeah, it feels low, but it's the only "cricket density" I could find.
Naively, I would have guessed an order-of-magnitude more crickets per unit area - but that's the number I found.

And data from Texas feels like it could be a LOT different from Massachusetts.
Warmer, but drier? - I don't know which is more controlling.

On the other hand, if you had, say, 10,000 crickets in earshot, it seems like that would be deafening
posted by AsYouKnow Bob at 10:03 PM on September 9


I feel like we should also be able to do this by volume of sound.

I can find a lot of references in popsci articles that says field crickets chirp at 100dB, but you'd need a distance measurement to go along with that.

Assuming even density of crickets, you can create a sum that works out volume, observing that number of crickets at a certain distance increase based on the area formula for an annulus (so, a power of 2), loudness per cricket decreases with the power of 3 (because it goes in all directions), and decibels are a log scale.

Theoretically, given cubic (I stand by cubic) crickets at even distribution from the listener then there's an equation to construct for this...
posted by How much is that froggie in the window at 10:58 PM on September 9 [2 favorites]


And I'm not really sure crickets get that high up into trees, they can't fly can they?

Yep! Some of them certainly can. Particularly relevant: tree crickets can fly. "They use their wings to produce their chirping song, but unlike others they can actually fly with their wings. This helps them reach high spots in trees and bushes to escape predators" from this identification guide (which I grant you is not the most authoritative-looking source, but it's disappointingly hard to find information about American crickets that isn't geared towards how to exterminate them).
posted by ManyLeggedCreature at 2:16 AM on September 10


Crickets will have some habitat preferences by species. Like, a species that is on the ground is not also going to be in the top of a tree for the most part. They could also be more common on plants that they eat versus plants that they don’t. These factors can help explain why the overall density is lower than some expected. There are surely multiple species out there occupying different niches, but I’m guessing the calls of one species are predominate, otherwise you would have mentioned different cricket sounds.
posted by snofoam at 3:02 AM on September 10


Yeah, I was basing my density guess on like maybe grasshoppers in cut down corn fields and seeing things jump away. It's harder to imagine that there's only 1/10th of of a cricket per square yard/meter. If they are tree crickets... that could pump up the numbers a good bit as it sounds like there are a lot of trees and bushes rather close by which I don't associate with Texas.

I propose bondcliff hangs a yard/meter square box up in the air with a pull string and drops it then counts the number of crickets captured. Then we'll have better numbers.

If they want, it is sorta fun to have a cricket cage - Google Search and catch a couple for the night and release in the morning.
posted by zengargoyle at 4:13 AM on September 10 [1 favorite]


Thanks for bringing the discussion to species. "Cricket" may be an "undefined critter making noise at dusk in typical eastern US countryscapes", but you can try to use a musical ear to further break down what's going on.
Example: I once listened analytically to the evening noise outside a Virginia rural porch and found I could distinguish 11 sounds, which I assume were produced by 11 distinct species.

Listening to each of these sounds more attentively, you will maybe hear four or five specimens of each of these 11-or-so species beeping, chirping, bzaaping or LEEEEEEEEEEEEEEEEEEEH-ling at each other. Maybe you'll pick up these distinct noises up to 50yards around you, against a more diffuse background of further-awayans. Let's go with that for the sake of argument, assuming (optimistically) that 7 specimens of altogether 11 species are conversing around you at 50yards....seventy-seven. 250 at 100yards maybe? Or what zengargoyle says.

The obvious caveat concerning all the critters who (not that. Who) for reasons of their own don't participate in the party.
posted by Namlit at 4:20 AM on September 10 [2 favorites]


People might like this: How Different Species of Fireflies Blink - Smarter Every Day 274 - YouTube. There's evidently this species of fireflies in this particular forest that eventually synchronize so the whole forest blinks in sync. Warning, it's hard to get on camera really well but I'm sure in person it's a bit magical. Since we're talking bugs and stuff.

The problem with audio sampling is that it's omn directional so you could tell distance but could not distinguish whether it was one or two or three or .... crickets that happen to be X meters away. Unless you can also pin down the temperature vs chirp parameter of the species involved and assume a spherical uniform temperature across the area. Even then you would have to do multiple access with collision detection for overlapping chirps (hello old thick/thin wire ethernet) which could be a PITA.
posted by zengargoyle at 4:35 AM on September 10


I enjoy this Ask! Best of the web, with some assumptions, give or take.
posted by Glomar response at 4:49 AM on September 10 [1 favorite]


Oh, yeah, sound is linear or squared (not cubic): Sound pressure - Wikipedia. Just like a candle and gravity. Not volumetric cubed.
posted by zengargoyle at 4:51 AM on September 10


@zengargoyle bringing the raku! Raku has a mothybutterfly mascot so I’d trust that over Python which might snack on the crickets as it computes, artificially lowering the result.
posted by drowsy at 5:53 AM on September 10


We might also need an entomologist for this, considering differences in size. Crickets range from 3mm to 50mm in length according to Google. And I'm sure there are outliers (considering that in the South, some grasshoppers can grow to the length of a mid-size sedan). How would the territoriality of really big crickets impact their population density (or for that matter, ours)?
posted by invincible summer at 7:12 AM on September 10 [3 favorites]


42.
posted by tizzie at 8:26 AM on September 10


The number of crickets in your radius is notably less than the number of mormon crickets in the same radius in the thick of the following story:


When things go wrong when traveling by bike (as they do), I say "at least it's not mormon crickets!" Once, I was biking across the Nevada desert on Highway 50, also known as the Loneliest Road.

For three days, there was a unending swarm of mormon crickets.

About once an hour, a car would drive over some of them. The crickets would flock to the unending tire track slick to eat their dead. The road was almost completely covered. It was worse than any photo I could find online. Density got higher than 100%. Here's a Wikipedia photo that' could be from the same swarm I experienced (Nevada, 2006).

The mormon cricket is (technically a katydid and) related to the locust. It was a linear swarm of biblical proportions.

And they jumped. I was riding a recumbent bicycle, which means I was sitting low to the ground. I spent several days with these crickets jumping within inches of my legs. Try not to squat to pee! We literally had to pitch our tent on top of them at night.

Then they thinned, and disappeared entirely, and they were gone.

Thankfully, they didn't make the chirping cricket noise, and so they didn't forever spoil me to that lovely summer sound. Cricket density definitely varies.
posted by aniola at 10:15 AM on September 10 [2 favorites]


What if there are some katydids in the mix? Also so many different types of crickets in Massachusetts!
posted by spamandkimchi at 10:28 AM on September 10


Response by poster: Here's a Wikipedia photo that' could be from the same swarm I experienced (Nevada, 2006).

ok i'm a little bit freaked out now
posted by bondcliff at 10:47 AM on September 10 [3 favorites]


And yet, they didn't hurt me.

I killed countless of them. Say I traveled a hundred miles of crickets. There are 63360 inches in a mile. Say there was 50% coverage on the part of the road where I biked, which may be a low estimate or it may be a reasonable average, could even be high, I don't know. Assume 3 inches per mormon cricket. 100 miles x 50% x 63360 inches / 3 inches per mormon cricket = 1,056,000.

Over a 3-day span of bicycling, I personally may have killed a million mormon crickets.
posted by aniola at 11:52 AM on September 10 [1 favorite]


Response by poster: I lived through the great New England _____* Moth Invasion of 1981 so infestations sort of freak me out. (link is to a freaky video of said infestation)

Anyway, staying on topic, I've asked my wife, who is musical, to try to count how many distinct crickets chirps she hears tonight. Stay tuned.

*Metafilter won't let me type that word. I don't know if it's problematic in the context I'm using it in, but better safe than sorry.
posted by bondcliff at 12:58 PM on September 10


Response by poster: Ok, Amy says she hears at least five different types of chirps.
posted by bondcliff at 4:31 PM on September 10 [1 favorite]


The Entomological Society of America has a project to revise problematic common names for insects, including Lymantria dispar, which is now the spongy moth.
posted by zamboni at 7:53 PM on September 10 [5 favorites]


Some of the crickets you are hearing might be tiny frogs, or other things that are not insects.
posted by vrakatar at 9:48 PM on September 10


I don't need you to actually count the crickets.

Obviously; if you had you would have posted in Jobs.
posted by nickmark at 7:30 AM on September 12 [3 favorites]


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