- Feeling stressed or threatened: Guppies are naturally shy and can easily feel stressed by sudden movements, loud noises, or the presence of larger or aggressive fish. When stressed, they may hide as a way to protect themselves and feel safe.
- Seeking shelter: Guppies may hide in plants or other structures to escape from strong water currents or bright lighting. They may also seek shelter during periods of rest or when they feel vulnerable, such as when they are sleeping or giving birth.
- Social hierarchy: In a group of guppies, there may be a social hierarchy where some individuals are more dominant than others. Dominant guppies may sometimes chase and harass subordinate guppies, causing the latter to hide to avoid conflict.
- Illness or injury: Guppies that are ill or injured may become less active and spend more time hiding. This behavior can be a sign that the guppy is not feeling well and needs medical attention.
- Lack of food or water: If there is a shortage of food or water in the aquarium, guppies may hide as a way to conserve energy. They may come out of hiding when food or water becomes available.
- Presence of predators: If guppies are kept in an aquarium with other predatory fish or animals, they may hide to avoid being eaten.
- Tank size: If the tank is too small or overcrowded, guppies may hide to avoid conflicts or to find more space to swim freely.
- New environment: When guppies are first introduced to a new aquarium, they may hide for a period of time until they become accustomed to their new surroundings.
- Improper water parameters: Guppy's can hide as a way to express discontent with the state of their water. Some parameters to check could be water hardness, pH, nitrogen levels, etc.