I've just had my first ever moth scare. I knit a wool hat and left it in my closet for several months and recently discovered it was moth eaten. Luckily most of my yarn is stored in a different room (sealed in vacuum bags), but I wasn't sure how long ago I moved several of the skeins out of that closet. I examined them all and didn't see any signs of moth infestation, but I baked most of the wool ones at 55C in my 3d printer enclosure just in case.