I grew Carnivorous plants for years, specially vft's. They need very high light, good air flow, warm conditions and very very poor soil, many things will burns their roots, even tap water, although they are known as very hardy plants, theres a reason why most pot plant ft's never get too big, its the root damage, I would think that the waste from the frogs would burn the roots. Also the smaller frogs could get caught if the traps are big enough but Im thinking they will be stunted in terrainium conditions. Your better off cutting the flowering heads off too, it will make that plant alot stronger and develop more, after flowing they generally die out. I used to split mine at the root rather then letting them flower, sections of roots can be frozen and thawed out in spring and they will grow well. I used a 400w eco grow lamp to give them a boost before spring set in completely, I had some big traps, small bird and mouse worthy