Hellbenders are normally solitary animals with a fixed home range.   Once a hellbender has established a den, it will rarely leave it except to hunt or to find a mate.  The territories of two animals may overlap, but the two hellbenders are never found in the same place at the same time; should they meet by chance, they will challenge each other.  A larger animal will chase a smaller one away, but two equally matched hellbenders will engage in a vicious fight (see bottom image).  And should one hellbender kill the other, they are not above cannibalism.