Bees understand the concept of zero
Check out this study from RMIT University that shows bees understand the concept of the number zero: The paper was published in Science: Howard SR, Avargues-Weber A, Garcia JE, Greentree AD, Dyer AG. Numerical ordering of zero in honey bees. Science. Vol. 360, Issue 6393, pp. 1124-1126 DOI: 10.1126/science.aar4975