How hard can a bat bite, and why does it matter? An insect-eating bat needs to eat about one third of its body weight in insects each night to fuel its fast metabolism, and bats with other diets (fruit, nectar, blood, etc.) have similarly high energetic demands. Therefore, biting and chewing foods very efficiently are very important nightly tasks for the survival of most bats. The strength of a bat’s bite roughly determines the kinds and hardness of foods it can eat in nature and thus, we can learn much about bat dietary ecology by studying their bite force.
In my experience, most bats are fierce little animals that do not like being handled by humans. This makes them perfect for measuring the strength of their bites. We do so by using a bite force transducer setup (pictured below). This device is able to register the force produced by a bat as it bites voluntarily; it converts the pull produced by the bite, applied on a tape-covered metal plate, into an electrical impulse that is read by a force amplifier.
In the field, we catch bats and immediately expose them to the bite force transducer, which they bite eagerly. Through this method, we have been able to document many important trends in the bite force of bats. For example, tropical bat species that specialize on very hard fruits, such as figs, are able to consume them thanks to the much higher bite forces that they can generate when they bite with their molar (cheek) teeth. Meanwhile, nectar-eating and vampire bats have very weak bites – their liquid diets have led to losing their ability to bite hard over the course of their evolution.
Article Source: Burke Museum