|"Feeling Blue": Common Blue Butterfly, Langdon Hills, Essex|
The larvae of this butterfly feed on Bird's-foot Trefoil (Lotus corniculatus). Adults will also feed on Bird's-foot Trefoil, and a variety of other plants besides (read more at www.ukbutterflies.co.uk).
Many of the butterflies in the Lycaenidae family have interesting relationships with ants. The chrysalis of the Common Blue attracts ants that protect it from predators. Larvae can also produce nutrients to feed ants (read more on Wikipedia).