Betta fish are known for their aggressive and territorial behavior, so its important to choose tank mates that are peaceful and wont trigger their aggression. Here are some fish that can live with bettas:

1. Snails: Mystery snails and Nerite snails are great options as they clean up algae, consume uneaten food, and have a hard shell to retreat into if the betta gets curious.

2. Shrimps: Cherry shrimp, Amano shrimp, and Ghost shrimp are all good options as they are small and peaceful.

3. African Dwarf Frogs: These frogs are peaceful and can coexist with bettas in a 10-gallon tank or larger.

4. Corydoras Catfish: These bottom-dwelling fish are non-aggressive and will live at the bottom of the tank.

5. Neon and Ember Tetras: These peaceful fish are small and colorful, and should be kept in a school of at least six.

6. Harlequin Rasboras: These fish are peaceful and have a bright orange body with a distinctive black triangular patch.

7. Kuhli Loaches: These eel-like fish are great scavengers and tend to hide together in groups during the daytime, making them a good choice for more aggressive bettas.

Its important to note that the tank should be large enough and have lots of cover and live plants to prevent the betta from becoming overly territorial. Also, avoid fish that have bright colors, large flowing tails, or are notorious for fin nipping, as these can trigger the bettas aggression. Finally, avoid predatory fish and fish that are territorial and aggressive, slow, brightly colored, or have large fins.