The reasons why koi lie on the bottom and don't like to move may be due to the following reasons:

1. Water quality reasons: It may be that the owner has not changed the water for a long time, causing the water quality to deteriorate, thus causing the koi to lie on the bottom.

2. Caused by illness: It may be that the koi is suffering from some diseases, which causes it to lie on the bottom and not like to move.

3. Caused by inadaptation: It may be that the koi cannot adapt to the new environment, which leads to this phenomenon.

4. Hypoxia: The filtration system in the fish tank is not perfect or the breeding density is high, which will lead to a reduction in the oxygen content in the water. Lack of oxygen can easily cause koi to lie down in the tank.

5. Rest: Koi will also lie on the bottom when sleeping and resting, but generally it will not last long.

Tip:

If the koi has been lying on the bottom for a long time and has not recovered, it means that the koi is likely to be sick, and the owner should treat it in time.