Lots of species only feed on one type of tree or bush. Or your veggies. So maybe look and try to ID what it was eating cuz there may be more attacking your tree or whatever. They usualy need another type of plant/tree to pupate and become adults. So maybe thats what it was trying to do there. Keep an eye open for more and for cacoons. Most species need three types of plant to complete their life cycle. Hope that helps, you must have all three types close.