What's the hardest thing to catch?

A squirrel has invaded the pitch… not once, but twice. Dave and Fionnuala can’t get over the scenes at Hull City vs Bristol City, where the ground staff were left trying (and failing) to catch it.From there, it turns into a surprisingly passionate debate: what are the hardest things to catch? A coin that’s rolling away, a receipt in the wind, loose paper money, chickens, sheep… and, inevitably, children who’ve decided they’re not going anywhere.