Are Hermits really reef safe?

[Matt]

I guess it depends on your model of "reef safe", and the species of hermit. Almost all crabs are opportunistic omnivores, but some prefer veg and some prefer meat. I've had tiny blue-legged hermits that enjoyed the taste of candy-cane corals, and they'll definitely kill snails. My experience is that they can/do learn. If one starts to eat your polyps, it seems to become a hobby for more of them.

Temper that with the truth that they're small and bold and slow. If they become a problem, you can deal with it easily. Normal growth and regeneration will normally outstrip any damage they cause.