During World War I, rations were doled out carefully, but food in California was being consumed voraciously by ground squirrels. School children were urged to aid the war effort and wage a war of their own by killing squirrels during a 1918 promotion called "Squirrel Week." Above is a pamphlet distributed to schools that contained information on the programmed instructions for using strychnine. There were even cash incentives for the kids who killed the most squirrels.
Children were asked to verify their kills by bringing in squirrel tails to their schools. Some impatient exterminators delivered their trophies directly to Commissioner Hecke even before Squirrel Week kicked off, causing a “pronounced odor” in his office. He requested that children not send him any more tails, and instructed his county commissioners to bury all tails after tallying them.
By the time Squirrel Week ended on May 4, children across the state had turned in 104,509 tails, though this was thought to represent a fraction of the total casualties. Even after the contest ended, the Commission of Horticulture reported that kids’ enthusiasm for killing squirrels continued for “an indefinite period.” During an anti-squirrel campaign in Lassen County later in the year, one girl brought in 3,780 tails; a boy brought in 3,770.
Read about the kids who killed ground squirrels for America at Atlas Obscura.