Readers weigh in on mathematical animals and more

Your letters and comments on the December 10, 2017, issue of Science News

Critter calculations

Savvy for judging quantities is turning up across the animal kingdom — even among spiders and other invertebrates, Susan Milius reported in “Animal math” (SN: 12/10/16, p. 22).

Some astute readers pointed out that designing experiments to test animals’ quantitative skills takes great ingenuity, but sometimes human bias may skew the results.