Marine organisms, beetles and a mouse embryo - they're there, but we can't see them. In fact, this isn't a case of "if you look hard enough you'll see it". These images are some of the finalists of the 2013 annual Nikon Small World Photomicrography Competition, which sees hundreds of photographers from around the globe competing to capture the miniscule life forms around us. This year's winner was Wim van Egmond of The Netherlands.