I found this little rotifer called Keratella, looking like an armour-plated Klingon warship, or maybe a medieval chain-mail glove, in a moorland pool about 500 metres above sea level in Weardale. Under the microscope it looks like a swimming claw, propelled by those whiskery looking hairs that you can see between the armoured ‘fingers’, which also serve to produce a water current that sweeps minute food particles into its jaws. The red spot is a light-sensitive eye spot. Most amazing of all, that egg-shaped object being towed around behind one of them is an egg – but not just any old egg. These animals reproduce by cloning themselves and never reproduce sexually, so the individual inside the egg is an exact genetic copy of the adult animal it’s attached to. When I peered down the microscope, I could see this animal’s alter-ego squirming inside the egg, ready to hatch. Keratella is about a quarter of a millimetre long.