My Father In Law has an elderly bitch (about 16) she was speyed many years ago. All of a sudden this last week she has started madly "humping" her bed. We have never seen this behaviour in her before. She never meets other dogs just spends her time pottering round the garden. Father In Law is 93 so doesn't walk her now. So it isn't anything to do with other dog smells. Has anyone seen this behaviour before? I know younger and unspeyed bitches do this and it is normal. Any ideas, thanks.