Pregnant women, look away now. When the fertilised egg of the womb begins to multiple its cells, it forms a ball of cells, know as a blastula. Then this alien thing folds in on itself to become a gastrula (theres a poem in here somewhere). The gastrula has an opening at one end, which begins to pinch together and close up, forming your very first body part: your anus. So if youre pregnant at this moment in time, it may be that a teeny tiny bumhole is being formed right now. So next time you tell someone in a rage that theyre an absolute a-hole, think again. Because technically, you were once one too.