Background
There are only three known species of shrew that utilize echolocation however there is still some debate about how much these shrews actually use it. There seem to be two main ideas of how the echolocation is used, hunting and 'seeing' surroundings, though which is more likely depending on which species is being discussed.
Shrews emit ultrasonic squeaks that are lower amplitude than bats, broadband, multiharmonic and frequency modulated. This means that there are no clicks with reverberations causing many scientist to believe that this echolocation is mainly for close-range spacial orientation. However, the shrews that utilize echolocation do not differ physiologically from shrews without it.
Shrews emit ultrasonic squeaks that are lower amplitude than bats, broadband, multiharmonic and frequency modulated. This means that there are no clicks with reverberations causing many scientist to believe that this echolocation is mainly for close-range spacial orientation. However, the shrews that utilize echolocation do not differ physiologically from shrews without it.
Diet/Echolocation
Because shrews must eat so much they often hunt for food throughout the night. Shrews tend to be excellent foragers in the darkness, which was odd due to their very poor eyesight and average hearing and smelling ability. This is part of the reason that leads some scientist to believe that shrews may use echolocation for hunting, however other scientists argue that they merely use it for spacial orientation to help them find their way to food and avoid predators. There is still research being done to determine what shrews use echolocation for, but it is agreed that they do not use it for communication purposes as whales and dolphins do. This research is important in order to learn more about echolocation, which could allow the improvement to technology we have such as submarine radar