SANTA MONICA, CA - MARCH 06: A ground squirrel looks for food at Palisades Park where the city plans to give the squirrels birth control shots to prevent a population boom on March 6, 2007 in Santa Monica, California. The city has been cited five times by the county for squirrel overpopulation. The squirrels are breeding now, from February to April, but plans call for squirrels to be injected this summer with an immuno-contraceptive vaccine developed by the U.S. Department of Agriculture called GonaCon to stop ovulation and lactation in female squirrels and halt testicular development in males. The city has used poison, gassing, and euthanasia to control the population but those actions angered pro-animal activists who favor non-lethal methods. Berkeley, California is the only other city to use this method so far.