Creepy crawlies

Part of the Ninewells walk by the Whiteadder this morning before spending most of the day sorting some more paperwork.

Yesterday we had a healthy-looking willow tree. By lunchtime today these little critters had chomped their way through an awful lot of the leaves. Assumed they're caterpillars, but seems they're some sort of sawfly larvae. Off outside on an attempt at damage limitation...