I was walking from Cowes on the Isle of Wight to Yarmouth along the coastal path in June. When nearing Yarmouth we saw this strange spike standing upright on a leaf (see photo). The top of the spike has broken off to the right.What created it? If it's of any use, the weather was warm.David Winstanley, Norwich, UK
Why are girls, and particularly young girls, drawn to the colour pink? Is it something society has instilled in them? Or is there something attractive about the colour itself? Shops seem to be full of pink clothes for young girls - are they reacting to demand or just forcing their designs upon children who would not otherwise choose this colour?Anna Garrard, London, UK(Image: kirsche222, stock.xchng)
Why do some birds stand on one leg?Alexander Middleton, Moorooka, Queensland, Australia(Image: bugdog, stock.xchng)Thanks to all those who offered the answer: "If they picked up the other leg they'd fall over." The old jokes are still the best - Ed
The Last Word has told us what percentage of the UK's surface area is roads (24 January 2004), but having just returned from the Netherlands I would like to know what percentage of the surface area of that country is water.Byron Hambleton, Lille, France(Image: NASA World Wind)
My son has a game in which you hang small plastic monkeys and gorillas from a plastic network of tree branches. The branch network is attached to an overhanging trunk by a magnet. As more monkeys are hooked on, the network becomes more unsteady until the magnet can hold it up no more. The player who breaks the bond is declared the loser.The game depends on a magnet of a clearly defined strength. But how is this strength determined so accurately during manufacture that it can hold almost all the monkeys (but not quite)?Pavel Sypchenko, Kiev, Ukraine
I was trying to take money out of an ATM and I couldn't remember my four-digit PIN. I use these machines most weeks and I don't have to think about my PIN - I just enter it.About half an hour later the number came back to me and I immediately knew that it was correct. What caused this brief memory lapse and what happened later to allow me to remember my PIN?Tomek Rej, Carlingford, New South Wales, Australia
In New Zealand one of our radio stations broadcasts native birdsong each morning. It is obvious that seabirds have a much harsher screeching sound than the more melodious bush and land-based birds. In fact, I can usually tell a bird's habitat simply by the sound it makes. Why is there such a difference, and is it the same throughout the world?John Finlayson, Maungaturoto, New Zealand