They want to explore the world around them, and they want to know what it feels like to be in different places. This is why cats scratch things. It's about marking territory, but it's also about getting rid of the dead part of their nails. Scratching also helps cats express their emotions. They're just like humans: when they're excited or stressed out, they scratch more than usual. Scratching can also help with stress—it's a good way for cats to get a good stretch after being cooped up in a small space for too long!