Well i took a chance and ive got two green tree frogs and 2 american toads and 2 house geckos.. I know its not a good idea to mix them but they been in the same tank since august and i have yet to have any problems. the toads and the gecko share this big log thing i made and the two frogs hang out on it every once in a while but they mostly hang out in the flower pots i have molded on to the sides of the tank. but yea i just decided to try mixing them with each other and the local vet said as long as i keep it at the good temp for all of them then they should be ok. But to also keep an eye out for none of them eating, which there all fat as hell and eat any thing they can get into there mouths. lol. Oh and the tank was a 55 gal that my friend had made him selt for his salt water fish. right now im using a 45 gal tank.