What's attracted him?

For the answer to the question 'What's attracted him' see the extra photo.
Not a good photo of the young robin, it was taken through a triple glazed conservatory window. The extra was taking kneeling on the patio amongst the wingless ants scurrying around. Ants in the Pants? probably!

There were lots of the winged ants on the lawn and we watched them for a while. stopped looking for a few minutes and they were all gone, off to start new ant colonies elsewhere.
Didn't know that mating takes place 'on the wing', whereafter the males die and the females lose their wings and overwinter in the ground. When the weather warms up they produce their eggs and the cycle starts all over again. 
Incredible really.