I suppose spiders will eat them, but unfortunately we found a big spider dead in one of the sticky moth traps dh distributes all over the house. They seem to catch a lot, but we still get them.
I've had the buggers chew holes in some really nice wool and alpaca knits. Now I keep any such thing in plastic bags, with a squirt of moth killer added.
There are some fairly noticeable holes in sitting room and dining room carpets. Until very recently I was telling myself that we'd replace them (they're quite old anyway) once our still-small Gdcs, who stay now and then, were mostly past the very messy stage.
However that will now be postponed quite a bit longer since a no.3 is due in January!
Heigh ho. Who cares about a few moth holes anyway....