Blind mole rats have been observed using both their sense of smell and their balance to navigate over short distances. Tali Kimchi of Tel Aviv University and her colleagues tested the creatures ability to stay on course during longer treks from home. The researchers brought wild mole rats into the laboratory and tested them in two types of mazes. In the first, a central hub surrounded by eight spokes, the animals were required to return to a specific starting point. When the scientists altered the surrounding magnetic fields using external magnets the animals were less likely to perform the task correctly, the team reports. In the second test the animals were placed in a rectangular maze. Under normal conditions, the animals effectively sought out a shortcut. Once the magnetic field was altered, however, their attempts to find the shortcut were less successful.
With the new work, the blind mole rat joins the small league of animalsincluding birds, fish and turtlesthat uses an internal compass to read the earths magnetic field. The mole rat employs the ability only on treks far from home, the researchers note, and updates its position throughout its travels to avoid getting lost. In light of our current knowledge, they conclude, we believe that other subterranean species, and possibly also surface-dwelling nocturnal animals, may have evolved the same highly accurate navigation system.
