X2!We had several kinds of night time critters before we got chickens. We have always had storage sheds and shop buildings and any and all critters love to dig under them. We had such a problem with rats and skunks that our local animal control would deliver us traps and we would set them and they would pick them up. Finally and old timer told me to by a 49 cent - it was then - bottle of ammonia and put it in a sprayer. Spray everything that you could. I did - around our fences, out buildings, house, etc every night or two. If it rains it washes away - no harm to anything - so you have to respray. My husband put it in a pimp up sprayer and I sprayed alot! In about a month we had no more critter problems. We had a house down the street a while back that was infested with rats and when they came to tear it down I started spraying again. Never saw one!