Red Eyed Tree Frog Feeding Question

[Chaser]

Alright, well I recently put in a smooth plastic cup in Phelix's tank. But so far none of the crickets are gone. Its been in the enclosure for a week.. I'm just baffled, originally this was how he got his crickets, then I ran out of cups (I replace them for sanitary reasons) and was tight on cash. So I got a whole bunch more and now he won't eat.
I don't know if he can't find it or what. But its starting to worry me.

[DonLisk]

Does the cup support the frogs weight if perching on the side of it? He has to be able to sit at the rim of the cup and pick them off from the top or get completely in with the crickets.

[Chaser]

The cup is a ways in the substrate, usually perched on the rim and got the crickets.