I've discovered I can't just try to feed a kit with a foster mom at any old time. Tried several times and the kit was sucking but got no milk. Looked like the kit would starve. I tried to let the kit feed first thinking it needed fed before the older kits. Still no milk. Finally I placed the new kit in her nest with the 2 week olds just before feeding time Afterwards the kit ballooned about twice the size.