This star-like nose also enables the mole to smell underwater, something which was previously thought impossible in mammals, which requires the inspiration of air during olfaction to convey odorants to the olfactory epithelium. Although the star-like structure is not a chemoreceptor itself, it helps the star-nosed mole blow between 8 and 12 small air bubbles per second, each 0.06 to 0.1 mm in size, onto objects or scent trails. These bubbles are then drawn back into the nostrils, so that odorant molecules in the air bubbles are wafted over the olfactory receptors. The speed of the bubbles is compared to other mole's speed of sniffing. Scientists found that the bubbles are being blown towards targets such as food. Before the star-nosed mole, scientists did not believe that mammals could smell underwater, let alone smell by blowing bubbles.