Red-sided garter snakes form a mating ball outside their winter den in Narcisse, Manitoba, May 14, 2008. Tens of thousands of snakes exit the dens in the spring to perform their frenzied mating ritual before dispersing to nearby marshes.
Fred Greenslade / Reuters

Student Jeffery Arndt watches a red-sided garter snake outside the snake's winter den in Narcisse, Manitoba, May 14, 2008. Students and tourists visit the site where tens of thousands of snakes exit the dens in the spring to perform their frenzied mating ritual before dispersing to nearby marshes.
Fred Greenslade / Reuters