Trails on plastic lid

Trails on plastic lid

Observation - Trails on plastic lid - UK and Ireland. Description: Beautiful fine toothed zigzag trails where apparently something has been grazing on the thin dry green layer of moss / mould / slime on the plastic lid of a recycling box. 2p coin included in one photo for scale. The climate here is very damp. Is it perha

Beautiful fine toothed zigzag trails where apparently something has been grazing on the thin dry green layer of moss / mould / slime on the plastic lid of a recycling box. 2p coin included in one photo for scale. The climate here is very damp. Is it perhaps a slug or snail which has grazed? Do they leave this sort of trail?