i'd say they are after moths. that would be a good thing.
from wikipedia:
The frog's diet is made up of mainly crickets, but they also eat mealworms, waxworms, fruit flies,flightless fruit flies (genetic mutation),fireflies, pinky mice (only for adults),house flies, moths, and possibly small amounts of fruit. The rule for insects is that the length of the insect has to be small that the length of the width of the head. This rule also applies to many other species of frog and lizard.