Birds at sea were able to smell krill-flavored vegetable oil slicks on the water.
The bloodhound is thought to have the keenest sense of smell of any dog.
When German shepherds were tested against people in smelling alpha ionone, a compound found in raspberries, the dogs were 10,000 times more sensitive than human beings (Marshall et al.
Olfaction, the sense of smell, is the detection of chemicals dissolved in air.
A given smell can evoke very strong emotions that cause one to pick up a particular flower and continue smelling and reminiscing over a long period of time.
An alternative series of classifications has also been put forward, based on data from an instrument (the OMEGA Visible and Infrared Mineralogical Mapping Spectrometer) on board the Mars Express orbiter.
The chemicals that evoke a sensation of smell are called aromas, fragrances, odors, or odorants.
Many mammals have a good sense of smell, and it is especially well developed in the carnivores (e.g., cats, dogs) and ungulates (e.g., cattle, deer, pigs).