In my opinion, there are three reasons why cats roll in dirt:
- To clean their fur
- Because it feels good (because the ground is uneven and it gently massages their back)
- To transmit chemical signals – pheromones – onto the ground as a way of marking territory.
You won’t find an answer to the reason why cats roll in the dirt (dry earth) in the very best books on cat behaviour (but there are tons of answers on the internet). And I have the best books on cat behaviour. I have just checked them and although cats roll around on their backs for various reasons under a variety of circumstances, the books that I have do not refer to this form of feline behavior.
Therefore, I have to fall back my own experience and knowledge of the domestic cat to find a reason. Please feel free to chip in and contribute.
Feels nice – massage and scratching simultaneously
I will take the second reason first. There is no doubt that cats like to roll and squirm on their back on dry earth, dirt and concrete. My cat likes to roll on concrete and the dry, sand soil at the back of the garden. He just likes the feel of it as it is quite rough.
I don’t believe that cats do this on entirely flat, smooth surfaces unless they are being petted. Therefore, I’d suggest that it is the uneven nature of the dry earth or dirt which is pleasant to a cat and which gently massages them. It may even provide a scratching sensation. If the surface is flat then the massaging effect won’t occur. It is quite apparent that cats love it.
Cleaning fur?
As for cleaning the fur, dust bathing is quite a common animal behavioural characteristic. We see it quite a lot on the television with respect to various animals including birds. I think it reasonable, therefore, to argue that domestic cats bathe themselves on dry earth. Perhaps they are also trying to get rid of parasites such as fleas. But my cat does not have any parasites on his skin but he still loves to dust bathe as a preventative measure perhaps.
Hens dust bathe! And I think cats do it for the same reason: to remove parasites and dead skin cells. The dirt particles attach to parasites and dead cells. When they shake themselves afterwards both fall out or they fall out naturally. The problem for me is that he deposits copious amounts of dusty dirt onto my white sheets when I am working on my site . The picture below tells the story.
Scent marking
As for the transmission of scent, I’m confident that domestic cats sometimes roll around on dry earth to mark territory by depositing sent into the earth. Before my cat rolls around, he smells the earth. He selects a place which is suitable and he smells that place. He’s probably smelling the scent that he himself has deposited on the ground and then reinforces it by rolling around in the same place. The more typical way of scent marking is through the spraying of urine, we know that. But I do believe that rolling in the dirt is another but less usual way. There are scent glands on the body which come into play.
Therefore, there are several reasons why a cat rolls around in the dirt. I sense that the primary reason is that the domestic cat enjoys doing it. That’s the main motivator.
P.S. The small images are thumbnails. If you click on them, you’ll be taken to a larger image and some words.
Below are some pages on unhappy cats.
Spot on, again. Also, I too often have to fall back on my own observations (I stopped looking at the books… been there done that.). Something further though. I think the slippery-ness of the dirt is a factor; that it allows them to wiggle a little. I used to watch horses do this all the time, too, and they would not do this unless it does that, else wise they would scrape their skin or pull their hair out.