Do I need to worry about hornets?

June 9, 2021 2:40 PM

I just moved to a new house and this morning I woke up to find a giant hornet -- about 1.5 inches long -- in my room.

The windows and doors were closed all night so I have no idea how it got in. I opened the window and it eventually flew out. Can I forget about it now or am I likely to see more of them? I'm in Guildford, UK if that makes a difference.

posted by Chenko to Pets & Animals (6 answers total)

Unless you spot others around your house, I wouldn't worry too much. It probably blundered in by mistake.
posted by pipeski at 2:46 PM on June 9, 2021 [2 favorites]

Best answer: Is it just getting warm out there? I've had multiple paper wasps queens, yellowjacket queens and what I assume was a hornet queen pop up as the weather has gotten warmer this spring. The queens overwinter while the rest of their colony dies, and a lot of times they find their way into crevices in a roof and then forget the way out when they wake up. When they do wake up, they're only interested in getting out.

Hornets, being larger, need it to warm up more before they wake up.

So you may see one or two more if you had more than one overwintering in your eaves, but it's unlikely that you have an active hive inside your walls.

(I'm in the US, and had a European hornet wake up in my office about three weeks ago during the first heatwave here)
posted by thecaddy at 2:56 PM on June 9, 2021 [1 favorite]

Sorry, but species-specific traits matter here. You mean a European hornet like this? Or if something else please advise. Species ID is pretty important to determine if they can be decent tenants on your property. Eg Paper wasps are in an entirely different category from yellow jackets, in my experience.
posted by SaltySalticid at 6:03 PM on June 9, 2021

Response by poster: I'm pretty sure it was a European hornet. It has just started getting warm here.
posted by Chenko at 12:51 AM on June 10, 2021

There are only two hornet species you're likely to encounter in the UK. The European hornet, which is the usual yellow-and-black colour, and the Asian hornet, which has a very dark body and yellow legs. Asian hornets should be reported. There are also hornet mimics, such as the Giant horntail and the Hornet moth. The giant horntail is a large sawfly, and is harmless.
posted by pipeski at 2:18 AM on June 10, 2021

Best answer: Hornets do occasionally blunder into houses; everyone else in my family has had one come in through a window at some point. The windows and doors may have been shut overnight, but if they were open during the day yesterday, it could well have come in then, and been asleep by the time you went to bed.

Based on my experience of waking up in a room with a newly-established entry from a wasp nest, an experience that I would like NEVER EVER to repeat, if there were a nest somewhere problematic, it wouldn't have been just the one hornet you'd have woken to.

Incidentally, I'm phobic of wasps. In my own house, the only window I ever open is the one I've rigged up a fly screen on. I have a fly curtain between the front door and the rest of the hall. I have more insect netting over the bathroom extractor fans. The front door is closed unless I'm actually using it. And yet I *still* get the occasional wasp in the house, which is very terrible. I don't have the least idea how they do it. Teleportation.
posted by ManyLeggedCreature at 2:30 AM on June 10, 2021