Generally, the following aspects are used to determine whether a cat is in estrus:

1. Loss of appetite. Cats will be more excited when they are in heat, and their minds are full of wanting to find a mate, so they will lose their appetite and stop eating.

2. The female cat becomes clingy. Female cats often nuzzle around you and act coquettishly in various ways, begging for attention. Male cats become aggressive and will compete with other male cats for territory to consolidate their status.

3. The female cat has a raised buttocks. Female cats often have their buttocks raised high and their forelimbs lying on the ground. Some male cats will mount themselves on non-estrus female cats or soft objects.

4. Cats in heat will be irritable and restless, and they especially like to go out. When a female cat is in heat, the cat will become restless and like to go out. Sometimes when the owner is away, he will sneak out to find a suitable male cat for mating. Female cats will also keep rolling on the ground when they are in heat. When a male cat is in heat, his personality will also become restless, and he will sneak out to compete with other male cats for territory to consolidate his position.

5. Love howling. Cats are prone to emotional disorders and excitement during the estrus period. If they cannot find a cat that can be bred, they will become anxious and howl often.