These little frogs are common, tiny pets. They generally don't get bigger than 2.5 inches long. They do not reproduce a lot, especially in captivity.
African Dwarf Frogs make amazing pets, but are easily mixed up with African Clawed Frogs when young. This becomes a problem when pet stores are selling these frogs.
Unlike their tiny lookalike, African Clawed Frogs are big and agressive. Females grow to be 4-4.5 inches long. African Clawed Frogs reproduce rapidly and transmit the fatal fungus Batrachochytrium dendrobatidis.
Batrachochytrium dendrobatidis, also known as Bd, is a fungus that spreads among amphibians. Bd kills many amphibians and loose African Clawed Frogs make this problem worse by spreading the fungus.
Take a picture of the frog(s) to make sure they really are African Dwarf Frogs