New high-speed video footage has revealed the extraordinary dexterity with which rats use their whiskers. The rodents are able to move these groupings of feelers independently on each side of their heads, allowing them to navigate efficiently in the dark, the film shows.

It was previously assumed that rats lacked the ability to isolate the movement of their whiskers, says Tony Prescott at the University of Sheffield in the UK. To get a more sophisticated view of this animal behaviour, he and colleagues used high-speed cameras and muscle sensors to record how rats swept their whiskers across various surfaces.

When the whiskers on one side of the rodents’ face hit a surface, they slow down by around one-third, the team found. Meanwhile, those whiskers on the other side begin rapidly sweeping back and forth, even more broadly, in search of another contact point (watch a rat’s asymmetrical whisker activity in this video, 2.3 MB, requires Quicktime).

Prescott notes that rats are nocturnal animals and therefore rely on their whiskers to help them sense their environment when it is difficult to see. It is like how a person would use their hands to navigate through a room in the dark, he says. In that situation, one might reach a hand out and hit a wall at which point one’s other hand would begin searching more actively to find out where the wall extends, he explains.

Journal reference: Proceedings of the Royal Society B (DOI: 10.1098/rspb.2007.0347)