When wildlife comes in from the cold!

As autumn changes to winter and the outdoor temperature falls, animals seek cover and protection for the winter months. Suitable habitats may include leaf litter, nooks and crannies on tree trunks, hedge-banks, walls and vegetation but they may move into built environments: sheds, garages and even our houses. These incomers may include rats and mice, which few of us would wish to share our homes with, but also numerous invertebrates, and it is these that I want to consider. Some butterflies overwinter as adults and occasionally emerge early from their resting places but unfortunately they are unlikely to survive. They will perish if put outside and use up valuable energy by fluttering about. Centipedes, millipedes and woodlice are more resilient, generally keeping out of sight, moving along the edges of floors and cupboards. And of course we have the spiders.....

All of these belong to the scientific 'super-group' the Arthropoda and have a hard waterproof skin that also doubles up as a skeleton (so they will crunch if you accidentally squash one!). Their bodies and limbs have multiple joints to allow movement, particularly the seven-segmented legs of spiders which are a marvel of bioengineering and are a fascination for some of us but probably contribute to the phobias that others feel towards these creatures, especially if they are hairy specimens. I suspect that many of us do have at least one phobia that we may not admit to but I am just pleased that spiders are not one of mine!

All spiders have a body divided into two main parts, a large fat abdomen and a generally smaller front half which carries all the sensory and feeding apparatus of the 'head' plus the characteristic eight legs belonging to the 'thorax'. Indoors, most spiders do not produce the elaborate orb-webs such as those of the garden spider but instead a much more chaotic sheet-web with a tubular retreat. The classic house spider is Tegenaria, the big hairy one with a leg-span of up to 10cm which makes its home in a neglected corner. Males often wander round at night but scuttle into the corner when you put the light on; they are searching for the more sedentary and long-living females. We also see a lot of the daddy-long-legs spider which resemble the similarly named insect only in terms of their long spindly legs. Their bodies are comparitively tiny and the webs they spin are quite extensive and filmy. There are another eight species commonly found indoors from a total of around 650 species that live in the UK, most of which are much smaller than those I have mentioned. Identification of the 10 'indoor' species is easy using guides on the internet and I would paricularly recommend those published on the websites (appropriately!) of the Natural History Museum and the charity Buglife.

All spiders bite and in the process inject a venom to paralyse their prey so that it can be stored and consumed over a period of time. They feed on many of the insects that enter our homes at this time of the year, so clear up the cobwebs if you need to but you may wish to allow a bit of space for these useful carnivores! Humans are far too thick-skinned to be bitten by the majority of spiders and a small area of inflammation is the worst ill effect to expect. When the noble false widow spider attained a certain notoriety in October this year, with some Birmingham schools being closed, this really was a false worry. With potential allergic reactions to bee and wasp stings, diseases carried by ticks and the bites of horse-flies and midges to worry about, spiders should come very low on the list of concerns.

Pete Mayston