Q: Given a scientific passage and an answer, generate a question for the given answer.
Passage: Mammals have important roles in the food webs of practically every ecosystem. Mammals are important members of food chains and food webs, as grazers and predators. Mammals can feed at various levels of food chains, as herbivores, insectivores, carnivores and omnivores. Answer: omnivores
A:
Mammals can feed at various levels of food chains, as herbivores, insectivores, carnivores and what else?