I don't know that I would count on them to eat plants. They were more than likely exploring. Frogs are obligate carnivores. Dwarf frogs have super poor eyesight so they'll taste anything that might possibly be food.
10 Gallon - "The Unfish Tank", Cherry Shrimp, 3 ADF, 2 nerites, 2 CPO
60 Gallon - "Technicolor Dream" Peaceful Community