Animal sex is as natural as anything can be. Two flatworms engage in a spirited round of penis fencing before one gets hypodermically inseminated against its will; a male antechinus takes part in a marathon sex session leading to its imminent demise; a giraffe checks in with a potential mate's urine to make some important reproductive decisions. In this episode of The List Show, Erin shares facts about animal sex that leave you better informed and perhaps unwilling to make eye contact with your cat.