Drowning toys in the water bowl isn’t uncommon behavior in cats, but we couldn’t find one definite explanation for it. Arnold Plotnick, a veterinarian blogging at catexpert.blogspot.com, and S. Hartwell, a writer for messybeast.com, both offer some guesses.
Our patron’s cat may be trying to store the toy in a safe place. If the toy is a particular favorite or if they’ve just finished with it, they could be “putting it away” in their food-and-water area, which they may see as a safe and central part of their territory. Wild cats will take their prey back to their nest, and the indoor cat dropping its toy in its dish could be following the same instinct.
Some cats like to play in water. Hartwell relates stories of cats that liked to pat the water with their feet and then pop the bubbles or watch the ripples, or a cat that would drop catnip in the water and watch the leaves float around. Our patron’s cat could be playing at fishing, or they could just like the texture of the wet toy.
According to John Bradshaw and Sarah Ellis in the books Cat Sense and The Trainable Cat, cats treat their toys like prey. They often like toys that resemble creatures they would hunt, and treat them differently depending on the size. They will be more cautious, for instance, with rat-sized toys, and tend to hold them at arm’s length rather than close in their front paws, as rats are more likely to fight back. Cats also tend to get bored with a toy unless they can damage it – a resilient toy that doesn’t show any sign of being “killed” indicates that it’s not really prey, or, if it is, that it’s too hard to subdue. As Bradshaw believes that cats think they are hunting when they play with toys, he would probably put the water-bowl behavior down to some kind of hunting instinct.