American Green Tree Frog's not eating as far as I can tell but one is suddenly fat?

I have 5 baby gray tree frogs and I haven't yet witnessed any of them eating. I've tried newt and frog pellets, frozen bloodworms, live crickets, chicken and even spam lol. The most interest I've seen them have is with the crickets. They'll watch them forever but if a cricket walks right in front of one of the frogs, kind of tickling the frog with its antennae, the frog just swats it away. I put one cricket in at a time. The first one drowned in the water dish. The last one I put in was still there the last time I looked (I put it in last night). I just put three more crickets in and now I'm waiting to see what happens. Anyway, last night I looked at one of my frogs and it was really fat and kept opening its mouth, almost like something was stuck in its throat. It seemed like it was gagging. It isn't opening his mouth anymore but still fat. I can only see two right now and the other one is really skinny.

Here's the fat one...


Here's the skinny one...


So why would the one be so fat and the other one skinny? Am I worrying about the wrong one??