When frogs eat insects, they are considered carnivores. Carnivores eat other consumers (meat), insects are meat.
Frogs eat insects, while insects eat plants. Based on the food chain, frogs are also considered secondary consumers.
Thus frogs are considered both secondary consumers and carnivore.
Plants(producers) eaten by insects (primary consumer), insects eaten by frogs (secondary consumers)
Consumers can be herbivores, carnivores, omnivore and decomposers.