As Gabrielle Nevitt explains, dimethyl sulfide is created when krill consume phytoplankton. And some birds in the order Procellariiformes — albatross, petrel, fulmar — are especially good at detecting dimethyl sulfide, perhaps up to 20 kilometres away.

They are called “fishes of the air” because they widely roam the oceans and only come to land to breed.

— Read more at Oceanic birds can smell what the ocean is cooking kilometres away, says U.S. research scientist at Vancouver Sun.

Scientists in Japan have identified a “smell sensor” in mice that triggers fear of animals such as foxes and snakes, a finding that could prove aversion to predators is genetically encoded rather than learned.

According to the study team, just sniffing their predators’ scents makes rodents freeze in fear even if they have never encountered them. However, which gene performs the function was unknown until the latest research.

— Read more at Scientists find ‘smell sensor’ that makes mice fear predators at The Asahi Shimbun.

“[This study shows that] bees can tell the difference between flowers where the only difference is their spatial arrangement of scent – and that suggests they could use that information to make their foraging more efficient,” said Dr David Lawson, co-author of the research from the University of Bristol.

—Read more at Bumblebees use perfume patterns to tell flowers apart at The Guardian.

A nearby colony of lovesick crested auklets are the culprits: Males produce a citrus odor to attract females. And as new research in Behavioral Ecology reveals, it's the strength of their citrusy scent along with the size of their crests that really matters.

— Read more at These Birds Make Their Own Citrus-Scented Cologne at National Geographic.