This 7 July 2020 video shows two Eurasian jays seeking out ants in order to have formic acid to clean their feathers from parasites.
Other birds, like black woodpeckers and blackbirds, act similarly.
Henk Ruiterkamp from Wijhe village in Overijssel province in the Netherlands made this video.
Pingback: Skullcap dapperling and birds | Dear Kitty. Some blog
Pingback: Mandarin duck, jays and nuthatch | Dear Kitty. Some blog