You wouldn’t think cats would go near a watermelon. But some cats adore them. I don’t know why but I can guess, although my guess is quite possibly wrong. I couldn’t find an answer on the internet.
Watermelons are sweet and juicy with quite a firm texture to bite into. The “meat” of the watermelon is red. They are a very healthy food for humans. I’m told that they contain an amino acid called L-citrulline, which the human body converts to L-arginine. I am not sure whether this is significant. Cat might like watermelons be because L-arginine very important to a cat. Perhaps cats are able to detect this particular amino acid in watermelons through smell.
Perhaps the most obvious reason why quite a lot of domestic cats like watermelons is because the “flesh” of the watermelon (the bit inside) appears similar to bloodied flesh. The firm texture may also feel a bit like flesh when eaten by a domestic cat. Cats like eating animal flesh, obviously. There is lots of water in a watermelon and the classic domestic cat prey, the mouse, is made up of 70% water. So there are similarities between the watermelon and the mouse!
One big difference is that watermelons are sweet in flavour. You would have thought that it would put off a cat. You may know, though, that the domestic cat cannot taste sweetness in foods and therefore it is irrelevant that the watermelon tastes sweet.
A domestic cat eating watermelon looks odd but it isn’t that far from a domestic cat eating a mouse from the cat’s point of view. The cat in the video is a Persian.