This form of feline behaviour is a reflection on the fact that adult domestic cats relate to their owners as their mothers. They might not relate to their owners as their mothers all the time but in this instance they do. Feline mums lick the rear end of their kittens to stimulate defecation. It seems that pre-weaned kittens don’t do it immediately and naturally and therefore their mother has to encourage them. They also remove the faeces from the den by ingesting it in order to keep the den clean. It’s a good bit of housekeeping and motherhood all packaged up into one action.
The kitten presents their bottom to their mother to do this. The action is stimulated by petting towards the lower end of the spine in the human-to-cat relationship. In the mother-to-kitten relationship in the stimulated by the mother grooming their kitten in the same spot. That is my explanation of it based upon personal experience and reading about the subject.
I have to say that it is a form of feline behaviour which is absolutely hardwired into the cat’s brain. You will invariably see it if you gently press down near the base of the tail. For obvious reasons, the tail is always erect. It’s a kind of rhythm: you press down on that part of their anatomy and they push up against your hand. It’s like flicking a switch, it is such a fixed action. It must be entirely inherited via their genetic make-up to do this.
It indicates that a newborn kitten is unable to defecate naturally without this form of stimulation. It is called anogenital licking (‘relating to the anus and genitals’). It is referred to as ‘maternal anogenital licking (MAGL)’.
Rats do it as well. It lasts up to weaning. In rats it stimulates “reflexive urination and facilitates urine production in the neonates”. “Neonates” are the offspring of the mother. The best of my knowledge, in the feline world, anogenital licking stimulates defecation not urination but I might be incorrect on that.
Martin Stucki who owned A1 Savannahs (a Savannah cat breeding cattery) with Kathryn, his wife, for many years, used to wipe the kittens’ bums for this reason. He took over the role of mother. I find that interesting because it begs the question why their real mother wasn’t doing it, or perhaps they were too.
SOME MORE ON MOTHEING: