Why do ants climb trees at night?

July 15, 2019 8:11 PM

I walk my dog three times a day, and because he spends a lot of time inspecting trees, I have little choice but to do the same. I often notice ants climbing up and down, but only at night. Tiny ants and huge ones. What are they doing? Why only at night? (This is in NYC.)
posted by moonmilk to Science & Nature (2 answers total)

Best answer: Carpenter ants build their nests in trees and are nocturnal. Members within a single colony are polymorphic and come in different sizes, so the large and small ants you see might be the same species.
posted by figmyg at 6:38 AM on July 16, 2019 [9 favorites]

I was in Costa Rica a while ago, and we took evening walks daily near our hotel and passed carpenter ants in long single lines carrying shreds of leaves from a tree, which they climbed, to their presumed nest, in a drain grate. The lines were the length of a city block, to and from along the curb - there must have been thousands - and the ants came out only at night. I don't know if they are simply a nocturnal species or if they prefer the cooler temperatures at night. They were never there in the day.
posted by citygirl at 6:52 AM on July 16, 2019 [1 favorite]