Deliberate mistake: In Paris' death scene, he blows alcohol onto his torch that illuminates the creatures around him. However the area is still illuminated after the light from his torch has disappeared. (01:12:05)
Deliberate mistake: In the scene right after they figure out that an eclipse would occur, everyone takes Shazza's drive to get back to the crash site. Right after the ride under the huge skeletons, you can see Shazza take a turn to her right but she was turning the wheel to her left.
Answer: Yes, it is her period. Considering that he lived in darkness for years, it's possible that he smells it too. It's also equally likely he realized she was a girl and that the creatures were all riled up and put two and two together. But the first explanation fits Riddick's character better.
Grumpy Scot