Reasons for guppies not eating:

1. The water temperature is too low. If the water temperature in the fish tank where guppies are kept is lower than 22 degrees, the appetite of guppies will change. At this time, the fish may not eat or like to swim.

2. Gastrointestinal discomfort. Guppies may suffer from gastrointestinal indigestion due to eating too much, or they may suffer from enteritis due to eating unclean food. These conditions will cause guppies to stop eating.

3. Suffering from disease. Guppies basically don't eat when they are sick. People with saprolegnia, oral rot, vitamin C deficiency, etc. will not eat.

4. The pH of the water is not suitable. Guppies like a weakly alkaline water environment, with a pH of about 7. If the water quality is too acidic or too alkaline, it will lead to a refusal to eat.

5. Pregnant. Female guppies also have poor appetite and stop eating during pregnancy.

6. Newly born fish. Newly born guppy fish do not eat, firstly, they have not adapted to the environment, and secondly, they have yolk sacs that have not been fully absorbed.