Cats are one of people's common pets, they have a unique personality and expression. When cats are happy, they show their joy in a variety of ways. Here's how cats behave when they're happy.

First, cats show their happiness through their body language. When they feel happy, they stretch out their limbs, lie on the ground or on the sofa, and make a comfortable purring sound. In addition, cats also use their tails to express their mood, and wagging or sticking their tails up is a sign that they are happy.

Second, cats' facial expressions also show that they are happy. When cats are happy, their eyes become more rounded and their pupils shrink, while the corners of their mouths rise in a sweet smile. Sometimes, cats will lick their cheeks with their tongue, which is also one of the signs that they are happy.

In addition, a cat's behavior can also reflect their happiness. When cats are happy, they become more active and enjoy playing, such as playing with balls, chasing spitballs, and so on. In addition, cats also like to be petted and cuddled, which is one of the signs that they feel happy and satisfied.

What’s more, the tone of a cat's voice can also show that they are happy. When cats are happy, their vocalizations become softer, more friendly, and sometimes they make a sound similar to "meow meow", which is a way for them to express their joy.

In the end, the overall atmosphere will reflect the cat's happiness. When cats are happy, they prefer to stay in a warm, comfortable place, such as a balcony or sofa, enjoying the sun and the company of their owners. In addition, cats also become more sociable and enjoy playing and interacting with people.

To sum up, there are many ways that cats show happiness, and we can feel their joy by observing their body language, facial expressions, behavioral habits, voice tone and overall atmosphere.