I've never mixed species, but I did some horrible stuff when I was little that I think I should share anyways. To thinking that toads somehow don't need water leading to the death of one of my toads when I was 8, keeping two American toads in a small 5 gallon tank and even keeping one in a container only twice its size when I was 6, I've made a lot of mistakes. I'ver learned now luckily...