“Wool-sucking is the act of feeding at a ghost-nipple….[and] lanolin acts as a powerful unconscious reminder of the mother’s belly…” – Dr Desmond Morris.
I think by now, most experienced cat owners understand that wool-sucking by domestic cats is most commonly seen among young cats who have been orphaned for some reason and deprived of their mother’s nipple too soon. In other words they have been weaned too early. The condition may persist for months and even sometimes for a lifetime. Siamese cats seem to be more prone to it. Is this linked to the Siamese cat’s loyalty and closeness to their human companion?
The interesting aspect of this condition is that early weaned cats suck wool. Why should they choose wool? They do choose other objects such as human earlobes and fingers or even their own thumbs rarely (like infants) but wool-sucking seems to be the preferred method of feeding at a “ghost-nipple”.
The attraction of wool appears to be the presence of lanolin. Lanolin acts as an unconscious reminder of their mother’s belly. When wool is sucked it makes it damp and this enhances the lanolin odour. This keeps the cat contented and fully engaged in their sucking and chewing habit.
Incidentally, Wikipedia tells me that lanolin is also called “wool yoke” or “wool wax”. It is a wax secreted by the sebaceous glands of wool-bearing animals. Lanolin provides waterproofing which helps sheep to shed water from their coats.
Wool-sucking is accompanied by kneading reflecting the behaviour of a kitten at her mother’s nipple when feeding. The cat at this moment is unaware of the world around him and is enjoying himself. Clearly it is a rewarding activity but there is a risk of ingesting wool which is probably why some cat guardians don’t like to see it and are concerned.
I’m sure that on the Internet there are millions of suggested cures for it such as punishment, diet changes or other fancy solutions. Dr Desmond Morris suggests that an aspect of this behaviour is stress and monotony in the cat’s life. He calls the behaviour “pseudo-infantile”. If he is correct then the solution might be to change the cat’s way of life to make it more stimulating, more interesting and more surprising. He believes that it might be due to an ’empty’ way of life. I think that he suggesting that it is more likely to be seen in cats living indoors full-time. If that’s true then it is another example of the extra demands and responsibilities placed upon people who wish to keep their cats indoors all the time. There is a general need to find ways to stimulate the brains of indoor cats.
The condition known as ‘Pica‘ which is eating non-nutritious objects is an extension of wool-sucking it sees to me. But there appears to be an overlap as Pica is also caused by an obsessive compulsive disorder.
Note and update 7/5/21: Doctor John Bradshaw, the author of Cat Sense disagrees with Dr Morris. He writes that he tested this theory directly and that “the idea did not stand up”. Perhaps the truth of the matter is that even the experts do not have all the answers regarding this strange cat behaviour.