Looking at our human population we know that about half of us are female and half of us are male. The way this 1:1 sex ratio is determined is by genetic means, you get an X from your mum and either an X or Y from your dad; meaning there is an equal chance to be a female (XX) or male (XY). This seems to be a good way to achieve an even sex ratio. However quite a few animals go about a far more daring way to determine the sex of their offspring. They let the environment do it — in particular by using the temperature.
The star-nosed mole (Condylura cristata) is a champion feeler. Native to eastern North America, these hamster-sized creatures do have eyes but they are much reduced so they are effectively blind. Instead, the moles rely on their uniquely weird star noses to find their way around.
Star-nosed moles live in underground (sometimes underwater) tunnels in wetland areas. They eat small invertebrates, aquatic insects and even small amphibians and fish. Their noses are key tools for finding their dinners.