There may be many reasons why cats like to chew on smelly socks. First of all, cats are natural hunters, curious about small animals and moving objects, and will try to catch or bite these things. Smelly socks can be an interesting "prey" for cats, who may bite them out of curiosity.

Secondly, cats may bite socks because they are bored or stressed. When cats are bored or anxious, they may look for ways to vent their emotions, and chewing on socks is one of them. Additionally, if cats don’t get enough of their meals, especially fat or fiber, they may crave nutrients from other items, including smelly socks.