Exciting things that I have learnt in Dublin

There are many seagulls in this place. They spend inordinate amounts of time hanging around college, much as the pigeons used to do at school and at my former college (except without the loud pigeon sex and the phenomenal amounts of excreta). Occasionally they walk about on the lawns.

It was only a few months ago that I realised that they rarely stand still. Throughout the winter (I wondered if their feet were cold, but they're still doing it) whenever they were on the ground they were constantly moving their feet so that one was always in the air. I don't know why this is (and I hope someone who understands seagulls will tell me in the comments) but they look like they're tapdancing. Are they? What gives, feathered tribe?