Have you ever seen ants carrying or dragging bird feathers?
Sometimes they even carry feathers that are much larger than themselves.
It also not unusual to see feathers on or in ant nests. See, for example, this cool photograph of a Pheidole oxyops nest with feathers from Flickr.
Seeing these made me curious. Why do ants collect feathers? Why do feathers end up around their nests?
It is very likely that different ant species may collect feathers for different reasons. A quick search of the Internet and books about ants offer some plausible suggestions.
1. To Obtain Moisture
Mark Moffett found Diacamma rugosum ants in India decorate their nests with feathers during the dry season. The feathers collect dew drops in the early mornings, which the ants can then drink and share with nestmates.
He also proposes that the dead ants spread around outside the nest might also serve for dew collection.
(Moffett, M.W., Adventures Among Ants, page 119 and Moffett, M.W. 1985. An Indian ant's novel method for obtaining water. National Geographic Research 1 (1), 146-149.)
2. To Obtain Food
James Trager rightly suggests on the Ant Blog that foraging workers carry feathers home because they (the feathers) may have small residues of bird tissue or fluids that the ants eat.
Here are some Solenopsis xyloni workers stripping the remaining dried tissues from a clump of wing feathers of a dead bird.
3. Anting by Birds Leaves Feathers Behind
Another likely explanation for bird feathers around ant nests is that birds have been known to flop on ant nests or even pick ants up and rub the ants on their feathers. This behavior is known as "anting." It is thought that birds interact with ants, at least in part, to remove parasitic lice, ticks and and possibly microbes. It is likely that anting birds might leave feathers behind on the nests, particularly if the birds are molting.
This brings us back to the possibility of the ants collecting feathers for food, because at least some feathers may still harbor lice, mites, or small ticks if they fell off the bird recently.
I have witnessed Forelius ants pulling a feather into a nest entrance myself, but it doesn't seem very clear how frequently ants collect feathers. It might be a relatively rare phenomenon or it might be fairly common.
Have you ever seen ants collecting feathers? What about ant nest "decorated" with feathers? What do you think about it?