Our cat had kittens five weeks ago and all was going well until last night. She has started hissing at them and hitting them with her paws and the back of her neck fur stands straight up when she is around the kittens. We are at a loss as to why she has suddenly rejected them. They are using the litter box and eating wet and dry kitten food. We have separated them and mom wants to be back where the babies are but when we introduce her back she starts her hissing and pawing all over again. Her behavior with us is fine as long as the kittens s are not around. Also her belly is all hard and lumpy I am assuming because she is not letting the babies nurse. Is there anything we can do or is she just done with them? We have homes for the kittens s when they are ready but I don’t want to give them away until they are ready. This is my first time having a cat that has had kittens so I am at a loss. Our cat is maybe a year old (she showed up in our shed last summer and stayed so we kept her)