Chalkhill Blue butterfly

We went to a local nature reserve this morning which is notable for its chalkland butterflies.  In the sunshine this morning, the steep hillside was alive with hundreds of Chalkhill Blue butterflies.  Here are two males on a wild pink cornflower.  In the extra is a male basking in the sunshine on the path.

They are the least blue of the blue butterflies.  The males have a flush of blue on the upper wings and the females are totally brown (and difficult to tell from all the other little brown butterflies).

This is one of the blue butterflies which has a relationship with ants.  The caterpillar exudes a honeydew which is "milked" by the ants who not only protect the caterpillars but also build earthen cells to protect the chrysalises!