Biology
The Role of Olfaction in Kin Recognition and Mate Choice in Mammals
Quick fact
Mice and humans can sniff out differences in a specific set of immune genes—the MHC—which lets them avoid mating with close relatives and even select mates with immune genes complementary to their own, boosting offspring disease resistance.
Why this is interesting
Ever wonder how a mother recognizes her own pup in a crowded colony, or how a mouse avoids mating with its own sibling? The answer lies not in what they see, but in what they smell.