麻豆社

Running through Bushy Park is the Longford River - a giant 'hosepipe' bringing water into the landscape. It's a canal dug by Charles I, and it still supplies water to Bushy's watery habitats. Chris Packham spots a shoal of sticklebacks doing something odd. There are hundreds of fish, and every now and then they spin over and show their light bellies at the surface. It doesn't make sense because that makes them very visible to predators, and they'll get snapped up. Some people think they are doing it to dislodge parasites such as leeches. Typically they do this rolling on the river bottom and rub the leech off. Why would they do it at the surface? A flash of sunshine is not going to get rid of a leech. Chris is baffled but happy - it's always fun to see something that you've never seen before.