Seagulls in southwest England are getting intoxicated from consuming flying ants, brazenly stealing food out of residents’ hands, flying directly into buildings and failing to get out of the way of cars. Apparently, the birds are becoming inebriated from the formic acid in the ants’ bodies, which lowers their inhibitions and disrupts their coordination, similar to the effect of alcohol.

Hot weather has helped spawn large populations of ants, upon which the seagulls feed. “That isn’t so good for the birds – it leaves them a bit drunk,” Rebecca Nesbit, and entomologist with the Society of Biology, said.

Formic acid is likely the reason for a strange bird behavior known as ‘anting,’ in which the birds thrash around, covering themselves in ants. The formic acid may help the birds repel parasites.

http://www.livescience.com/38336-seagulls-drunk-on-ants.html