Question: Can I Keep Bigger and Smaller Frogs of the Same Species Together?
While some species of frog are best housed alone, such as pacman frogs (ornate or Argentinian horned frogs), african bull frogs and cuban tree frogs, some other frogs will coexist quite well with others of their own species. Mixing species is a whole other problem and is also addressed below.
Answer: Generally, anytime frogs of the same species are housed together it is a good idea to make sure the frogs are of a fairly similar size. Frogs are sometimes quite voracious eaters, and are often not hesitant to try and eat a smaller cagemate. This is usually not a problem for most species of frogs when they are similarly sized, as long as the housing is large enough and the frogs have enough hiding places if they need some space from each other. However, if you have frogs that are significantly different in size, larger frogs may try to eat the smaller ones. Even if they are not successful in making a meal of their cagemates, this scenario will be stressful on the smaller frogs and may lead to injury.
There is no hard and fast rule about what constitutes a significant difference so you will have to use your judgment and keep and eye on your frogs if yo do house frogs of different sizes together. Make sure you provide enough space and lots of hiding spots if your are housing multiple frogs together, and at the first sign of problems, be prepared to house them separately!
Certain species as mentioned above, will most likely try to eat cagemates of the same species, no matter what the size. These include pacman frogs (ornate or Argentinian horned frogs), african bull frogs and cuban tree frogs.
A note about mixing species: I never recommend mixing species in a terrarium. Generally, there is too much risk of incompatibilities in environmental needs, resistance to disease, and/or behavior to take chances on mixing species. See more detail on my reasoning in the answer to "Can I Mix Species in a Terrarium?"
More about More: Frogs as Pets
