Data from: Numerical ordering of zero in honey bees

Some vertebrates demonstrate complex numerosity concepts—including
addition, sequential ordering of numbers, or even the concept of zero—but
whether an insect can develop an understanding for such concepts remains
unknown. We trained individual honey bees to the numerical concepts of
“greater than” or “less than” using stimuli containing one to six
elemental features. Bees could subsequently extrapolate the concept of
less than to order zero numerosity at the lower end of the numerical
continuum. Bees demonstrated an understanding that parallels animals such
as the African grey parrot, nonhuman primates, and even preschool
children.