the most likely culprit i would think will be caterpillars but i have known snails to slither up his sort of plant and have a munch now and again.

I have mine and 6 cuttings in the conservatory at the moment and they haven't been outside since I repotted or potted them on!! However, I have found holes and slimey little trails all over the leaves. I would say slugs/snails as caterpillars aren't around this time of year. Check out the leaves to see if there are any silvery trails