Pandas are terrible at sex. Today I learned that female pandas are only fertile for two days a year. For Edinburgh zoo resident Tian Tian, that brief knocking-up window started today. If pandas had any sense of responsibility to their genes, this would be the prompt for some mad panda action. They would be at it, and at it good. But no, because as well as being practically infertile by design (two days, pandas! What, did you confuse “menarche” and “menopause” when you were working out your evolutionary strategy?), pandas are also lazy, lazy lovers.