Oh no...just frogs that are of the same size and similar habitat requirements. I know a lot of herp keepers will not do that but if you go to zoos and see their set-ups...many of them mix animals. It's ok to do so as long as they are compatible with each other. I will mix toads with other toads tho, again so long as it is ok to do so.
Cuban tree frogs are one of them! They are a cute frog species but you have to make sure you house them with either exact same size or slightly larger frogs b/c they will eat smaller ones!
The majority of them are mine. I make a note in the comments of each shot if they are or not...but if there is one that I don't have stated either way let me know and I will fix that.