They glued stilt-like extensions to the legs of some ants to lengthen stride. The researchers shortened other ants’ stride length by cutting off the critters’ feet and lower legs, reducing their legs to stumps.
By manipulating the ants’ stride lengths, the researchers could determine whether the insects were using an odometer-like mechanism to measure the distance, or counting off steps with an internal pedometer.
The ants on stilts took the right number of steps, but because of their increased stride length, marched past their goal. Stump-legged ants, meanwhile, fell short of the goal.
Hopefully, no animal rights activists will be pounding on the facilities’ doors demanding them not to mutilate ants in the name of science 😛