Cat Two Cats Share Raising Kittens?

We have two cats who were due to be neutered in january, but they were pregnant by then! However, one delivered 4 lovely kittens a week ago, all well, feeding normally etc, mum very attentive. The other cat delivered two days ago and again 4 lovely healthy kittens. Neither cat nested for the birth and both chose to have them in full view of us and have been okay with being around us, they haven't tried to move the kittens to another room. What we would like to know is, is it normal for the cats to feed each others kittens? They will not be separated into their own beds and have chose to stay squashed up together with 8 kittens feeding on whichever nipple they find first. It is very sweet to see them cleaning each other and each others kittens, but we have worried that the second cat who only delivered two days ago may have found it all a bit too much as today we noticed that she seems to be neglecting her kittens a little. (Jenna Elliott - United Kingdom)

It is not at all uncommon for animals to share the milking and raising of closely-related or closely-trusted litters. Most recognition of young comes from the smell, and as such most recognition of young of another animal is the same. Thus, since all of the kittens are likely to smell of both females, both mothers will accept all of them. In most respects this will certainly not do either mothers or young any harm as long as they are both willing parties. Indeed, there are almost certainly advantages, such as being kept clean by the other mother. This will help them relax during quiet spells. Cats and dogs tend to go through spells of appearing less than enamored with their young, but almost certainly she is just a little tired. Behavior like this very rarely gets in the way of a good mother-offspring relationship.