Here is a tidy explanation of why birds don't fall out of trees when they go to sleep. It is in Why Don't Penguins' Feet freeze? the second of collection of questions and answers from the New Scientist's Last word column. It is supplied by reader, Anne Bryce:
"Birds have a nifty tendon arrangement in their legs. The flexor tendon from the muscle in the thigh reaches down over the knee, continues down the leg, round the ankle and then under the toes. The arrangement means that, at rest, the bird's body weight causes the bird to bend its knee and pull the tendon tight, so closing the claws. Apparently the mechanism is so effective that dead birds have been found grasping their perches long after they have died."
When I was young, ginger was available in powdered form, crystallised or as an ingredient of ginger beer or ginger wine, gingerbread or ginger biscuits. It is only relatively recently that the root has become widely available from greengrocers and supermarket. For the last few years, I have been peeling and chopping the root so as to scatter the pieces over our morning fruit. As I buy a chunky piece of root today, I realize that we are growing increasingly fond of the spice and and eating more of it daily. The tang which it leaves on your palate, as wine tasters say, has a long finish. Incidentally, if you keep a piece of root, it will begin to sprout. Planted in compost and kept warm, it will become a ginger plant.