I've fed my WTF several ways:
1) Put insects in a bowl. This works with small or clumsy worms such as waxworms, mealworms, superworms, small nightcrawlers (see below). The frog comes down at night and eats them. But then he also spends most of his spare time sitting in the bowl, waiting for food!
2) Hand feed him. I just hold a bug up, and he goes for it. Well, he goes for the bug and as much of my hand as he can stuff in his mouth.
3) Put him in a separate container. This works very well, and if my frog is stressed, he shows no signs of it. I think I could be setting of cannons and flashing strobe lights in the middle of an 8.5 earthquake, and he'd be concentrating on catching the bugs crawling around him.
I like to watch him eat, so doing of of the above allows for that. Otherwise it comes down to releasing crickets into the tank and letting him eat them in the darkness. If the crickets ever come out from under the moss.
And I've had him about 18 months and he's doing very well with this approach to feeding.

