Animal behaviour is interesting to read about, but more interesting if you witness it first hand and draw your own conclusions.
When you live in a very old farmhouse, as we do, there are many cracks and nooks where wildlife chooses to hide away. When we moved to our present home and replaced the windows, the new panes fitted into the spaces but needed some filling with an edge of mortar and over time the mortar cracked leaving spaces for wildlife. To our surprise we heard chirping, not just an odd chirp but an orchestra. Further investigation showed the chirping to come from geckos which, from time to time, emerged from their cosy home and ran up the outside walls with remarkable agility. They have pads and hairs on their feet which enables them to do this and indeed scientists have studied their feet to develop strong adhesives.
Geckos are cold-blooded so do not suffer cold but in winter they go torpid and only emerge from their homes occasionally.
One night, to our surprise, out came the geckos and ran up and down our window glass. At first we thought they were attracted by the light, but geckos are happiest in dark places like cracks in walls. Maybe they liked the heat from the lounge window and the wood-burning stove nearby. We were fascinated by the actions of these beautiful creatures. They inhabit countries with a warm climate so maybe it was heat they sought.
Careful study revealed the answer: they were after food. Insects are their main diet and insects are attracted by light. The geckos found a real feast on our windows.
I remember a few years ago when we were in New Zealand concern was expressed about the annual increase of insects which were coming from the uninhabited island of Crusoe. Apparently a cargo ship went aground on the island in 1949 with a load of fruit and vegetables which was offloaded to refloat the vessel and left lying on the island. Insects arrived to enjoy the rotting food and stayed there and spread their hunting ground.
A scientist called Mike Lee came up with a solution and captured thirty geckos which relished the harvest of insects. That was in 2010 and when we were in New Zealand recently the insect problem had been resolved.
Some people in Spain keep pet geckos to keep insects down. One householder told me he was worried because one of his geckos had lost its tail. No need to worry. If a predator makes an attack on a gecko its first reaction is to freeze. A further escape movement is to forfeit its tail, an action called autotomy. Another tail soon grows.
Yes, animal behaviour is indeed fascinating.