This generally works for teeth as well, the shape of teeth shows what kind of food an animal eats. Carnivores have sharp pointy teeth and generally big canines, herbivores have big flat molars and flat incisors, and where something falls between these extremes indicates what their diet probably is.

For example bears and humans are both omnivores, but bears have muuuuch larger canines while ours are.. maybe useful for gnawing off a small tendon i guess?
And lo and behold bears are carnivores that eat a lot of non-meat things, while humans are primarily foragers who'll eat meat when we make prosthetic canines to hold in our hands :^)