Do Blackbirds Like Mothballs?

To keep rabbits out of my flower beds, I often place some mothballs among the blooms. One day, I noticed blackbirds picking up the mothballs and rubbing them on their feathers. What were they doing?

—Caroline Deibert, Hagerstown, Maryland

George: Birds use mothballs to rid their feathers of lice and mites. It's a common behavior for grackles and European starlings, as well as members of the blackbird family. You may see these birds exhibiting similar behavior on an anthill. They squash the ants to produce formic acid, which helps the birds get rid of annoying parasites.