idk, they may have a sense of smell, however there aren't many signs to suggest it, especially that its a strong one. First off, the lack of any sort of visible nostrils (however, there is very much the possibility that they do in fact smell differently than us or anything on Earth).
Further more, while they are a hunter species, they may not have evolved to be hunters. That is, they don't need to hunt to survive. They do seem to eat meet (hypothesized in P2), however like humans are smart enough to use technology to hunt for food, and have a higher thinking and reasoning ability to outsmart their prey.
If they do have a sense of smell, there is no apparent reason it should be highly advanced like a bear or lion, or even a dog.