Ants
Read this in a weird and wild book of maths and scientific facts and experiments.
There was some research about whether ants can actually count. So, they created a colony and selected some ants who had travelled a distance from their nest. Some of these ants had their legs shortened through amputation and others had their legs lengthened by the researchers.
Upon dropping them back at the point they were picked up, they noticed that although the ants had a sense of direction which enabled them to walk back in the direction of their nests, those with shortened legs stopped short of the nest and thought they were home, and those that had had their legs lengthened walked straight past it as they (presumably) thought they hadn't completed enough steps before getting home.
Weird, eh?