You know your pleco is happy if it exhibits the following signs of a happy and healthy pleco:
- Healthy appetite
- Nice full or rounded belly, its abdomen should never look hollow
- Clear, normal eyes, not cloudy or bulging
- No injuries or abnormal growths
- No white spots or blemishes
Additionally, you should remember that plecos are nocturnal, bottom-dwelling fish, so your pleco might stay in hiding and avoid moving too much during the day. These are normal behaviors for plecos and shouldn’t be a cause of concern.