One of the popular anecdotes associated with drug-induced hallucinations is the feeling of being covered with bugs. Now I admit that I’ve had my share of bug-covered experiences (related to field work, not drug use), but it isn’t something that I actively search out. I was looking out of my window today and watched two Brown Thrashers digging themselves into the dirt outside. Now, that particular behavior could be the result of two different possibilities: 1. Dust-bathing and 2. Anting. Dust-bathing is a much more common sort of behavior. In this process, a bird gets on the ground and gets dust in and among its feathers as a means of helping to get rid of parasites. I’ve seen this behavior in a number of birds, but it usually involves a fair bit of movement, either rocking or actually jumping. These two thrashers actually nestled themselves into the grass and then just sat without moving, not a typical sort of dust-bathing activity. Occasionally, one of them would peck down into the dirt and then sit back down. After the birds left, I walked out to investigate their little holes and did find some ants in them.
Anting behavior is likely another way to clean. The ants are invited (ok, they’re tricked) into climbing onto the bird and biting the feathers. Why? Do the birds actually enjoy the feeling of ants all over themselves? Well, it’s actually more likely that the birds are treating themselves. Ants, when they bite, release chemicals. Some of these chemicals are quite potent and probably quite useful for the bird.
Revis, H.C. and D.A. Waller. 2004. Bactericidal and fungicidal activity of ant chemicals on feather parasites: An evaluation of anting behavior as a method of self-medication in songbirds. Auk 121: 1262-1268.
Ants are only one way to get these sorts of medicinal treatments. Other people have reported birds using millipedes, marigolds and mothballs in much the same way.
Personally, I’d take marigolds and mothballs any day over letting myself get covered by ants and millipedes.