So I currently have a 40 gallon bioactive tank with my 2 American toads. There is about 4-8 inches of substrate with spring tails and I will be getting isopods soon. There is a large pathos plant, large shallow water bowl, some other decor, and a UVB light. I was wondering if I could keep any other herps with them safely with no risk of any harm coming to my toads.
And of course the picture tax
I don’t know. Toads really try to eat anything that is small enough for them to eat. Maybe some other people will have better suggestions.
I love love love toads and yours are adorable! If it were me I would not rock the boat, so to speak, if they are thriving, which it looks like they are.
However, since you said you were going to add isopods, you could definitely have some fun with them. If you want to do some research on which different types of isopods can coexist with each other, you could add a few different varieties in with your toads. That would be the safest option imho…….
But others may have suggestions as well…… 
That is true. I am by no means dead set on adding another species but thought it could be interesting.
Honestly, it would be so much fun to add something. I really hope others have better options for you.
I agree, I think it would be too risky trying to add another herp species. But, if you want to make it interesting you could improve the hardscape of the tank or change around plants/isopods. I think a unique/colorful beetle species would be awesome in there.
Any suggestions?
You could also use millipedes or snails. Millipedes will be tricky if you do use isopods since the isopods will eat them when the millipedes molt. Millipedes will be very easy for the toads to eat, so those might be tricky.
As far as beetles, there are only a few species easily available. But, I think it’s worth looking into taxi cab beetles and jade-headed buffalo beetles, you can occasionally find them, but they will be expensive. You could get darkling beetles (superworm beetles), but you run the risk of the larvae chewing on the toad, which could be avoided if you feed them with fruits/vegetables.
IIRC, Toads will eat anything they can fit in their mouth, and if it’s bigger than that it will probably do its best to eat them. They’re a solid link in the food chain, as bite sized opportunists.
I was thinking about suggesting snails myself. I have a New Mexico Spadefoot Toad as well as a Dumpys Tree Frog. I wonder if snails would work in their enclosure…….? 
Sorry for bringing this topic back up but I was kinda thinking that dumpy tree frogs might work. They are both very similarly sized and almost identical care. What do you guys think?
