I know I have put this one on before, but it is such a good tip it needs posted every now and then. If your dog is digging under a fence or if some other animal is digging and you are worried about your dog getting out from under it, just buy a bag of Sakrete and put it under the fence. You don’t even need to mix it or take it out of the bag. The bag will hold the shape and moisture will seep in over the night and when it rains, curing the concrete. You will end up with a concrete barrier that looks like a pillow. The yellow bag will dissolve and rot. Cover the concrete pillow with mulch and no one will ever know its there. Dogs don’t like trying to dig it out, it is too big.