Dogs and cats: can someone explain this? Jack mostly ignores the cats

[hedgehog]

while Guinness is pals with MaryJane the little bitey cat. He allows her to groom him from time to time. He occasionally grooms her and the new kitten. He's happy to share the bed with any cats who care to join him.


We have a pet door out to the dogs' pen and a cat door on the covered porch. The cats go in and out freely because they can duck under the fence on the dog pen.

When the cats come back indoors, especially if they use the little cat door, the dogs go nuts wanting to sniff them. The cats hate this, and sometimes won't come inside as long as the dogs are watching them.