Question about a frog?

I have a small frog, no less than the size of my pinky fingernail (it lost all of its tail about 3 weeks ago) and I have it in a container with shallow water and lots of mud. I put in some bugs that I found, you know those tiny white jumping bugs, and he just won't eat them! So I put some very tiny wood lice in there, perfect size, and he won't eat them either! He won't eat mosquito larvae, small bloodworms, or any small bugs. What am I supposed to feed him now!? Thanks :)