There are certain sectors within the cat community that believe tom (male) cats will attack, kill and eat kittens, which has resulted in the routine segregation of males from nursing mothers and their young kittens. The truth is that although cannibalism is recorded in many domesticated species including mice, rabbits and dogs, such behaviour is rarely seen in cats.This belief has been held for centuries: Over 2,500 years ago the historian Herodotus visited ancient Egypt where the cat was revered as deity and recorded several observations of feline behaviour, including the infanticidal behaviour of the male. He concluded that this was the result of the tom cat's sexual obsession–by killing the offspring the male cat was attempting to make the female return to oestrus ("heat") more rapidly (a female who is nursing kittens will not come into heat).
The "cat-murderer" image has been perpetuated by reports of infanticidal behaviour in males of some of the wild felids, including lions, tigers, pumas and ocelots. It is commonly observed that a male lion who has taken over a territory that houses a female and her offspring may indeed indiscriminately kill her cubs. It is thought that such behaviour is performed to reduce the reproductive success of his rival (the previous king of that pride and father of these cubs), as well as to increase his own genetic survival by causing the female to return to oestrus so he can mate with her and ensure that these new cubs carry his genes. Mothers of cubs killed in such a massacre can actually come into season again within 24 hours of the event. This behaviour also ensures that the new male does not drain his resources by helping to feed and protect cubs with no genetic input from him.
Infanticidal behaviour has been reported in the domestic cat when living in social feral groups where the identity of the father is uncertain, but infrequently happens in our homes as in many cases the kittens have been sired by the resident male, or the male is a roaming (and therefore long gone) father.German ethologist Paul Leyhausen proposes that infanticide in the domestic tom may not be a deliberate act of murder but rather the result of a misunderstanding. A few weeks after kittening the female domestic cat sometimes exhibits a surge of hormones and goes into a false heat (pseudo-oestrus) which the male takes as an invitation to mate. However, the female is not receptive and rejects his advances and, in a state of sexual arousal, the tom mistakes the low, crouched position of the kitten for the sexually receptive stance of an in-oestrus adult female.
When the tom mounts the kitten he holds it in position by using the neck bite which is a normal part of mating behaviour and the kitten responds by staying still, perhaps confusing the male's neck hold for scruffing by the mother. However, when the tom is unable to mate with the kitten because it is too small, his reaction is the same as to an un-cooperative female–his grip on the neck becomes tighter and tighter until eventually the kitten dies.
Why a queen kills her kittens
There are a number of possible reasons why a queen (female) may kill her own kittens. In cases where the mother herself is malnourished, particularly in feral colonies, her drive for self-preservation may override her maternal instinct. Californian animal behaviourist Benjamin Hart recorded that litters resulting from the second pregnancy in a year are more prone to being cannibalised, probably because the mother has drained significant resources with the first pregnancy and is overburdened by the second in one year.Larger litters are more likely to be cannibalised as the mother dedicates her limited resources to a few kittens that have a better chance at surviving rather than spreading her resources too thinly and risking the demise of all of the kittens. Weak and sickly kittens are often killed because they are not worth the maternal investment if their chances of survival are slim to begin with.
Stress caused by overcrowding in multi-cat households lies at the root of many cases of cannibalism and this can be linked to failure of the mother to find a secure nest in which to raise her kittens. If she feels threatened she may destroy her kittens herself, therefore it is important that all breeding queens are provided with a quiet kittening area away from the hubbub of the house and from any other feline residents. She should be allowed access to this peaceful haven for at least two weeks before the kittens are born. Cannibalism may also result from aggression being redirected onto the kittens after the mother has been disturbed, either from outside or by another cat that has frightened her in some way. Animal behaviourist Michael Fox has suggested that if there is a failure of the cat's hormone system to inhibit prey killing, the queen may mistake her kittens as prey and deal with them accordingly.
Although abhorrent to us, cannibalism is rare in cats but is usually accompanied by a perfectly reasonable explanation. If your cat has a history of infanticide, I strongly recommend that she be spayed because it is thought that this behaviour is hereditary (meaning that it can be passed from mother to offspring). Most importantly, remember to provide your pregnant female with a secure resting area and supervise the feline family until the kittens are weaned.