While betta fish can be aggressive, they are not typically dangerous to humans. However, it is important to keep betta fish in separate tanks to avoid any potential conflict. If you are planning on keeping multiple betta fish together, it is important to provide them with enough space and hiding places to help reduce aggression.
How do bettas kill other fish?
Betta fish (_Betta splendens_), also known as Siamese fighting fish, are known for their aggressive behavior towards other fish, especially other betta fish. This aggression is due to their territorial nature and is a result of their natural instinct to protect their territory and mates. Bettas will typically attack other fish by flaring their gills, raising their dorsal fins, and charging at the intruder. They may also bite the other fish's fins or body, and in severe cases, may even kill the other fish.