'Unusual spiders' nearly always turn out to be British species, perhaps a particularly large example, unusual colour form or one that you have not seen before. Others will be foreign. These can be:
- Escaped pets (many of the 'bird-eating' spiders are kept by enthusiasts, as are African Imperial Emperor scorpions)
- Spiders or scorpions that have crept into your luggage whilst on holiday abroad and then emerged
- Spiders that have come to Britain in fruit, vegetables and other products.
Imported spiders in fruit from abroad include the infamous Black Widow. Several British spiders closely resemble this and are often mistaken for it including Steatoda paykulliana. See false black widows.
Banana Spiders, Heteropoda venatoria, also known as the Huntsman or Giant Crab Spider, are less common now; partly because of changes in the way bananas are harvested and transported. These large, brown, crab-like spiders have flattened bodies that enable them to fit into very small cracks and crevices. Heteropoda venatoria lives in tropical and subtropical regions but not Europe where it is too cold. It is transported throughout the world in banana shipments and is thought to have originated in Asia, where its closest relatives occur. This species is common and useful in houses in the tropics where they eat cockroaches and other insects. More importantly, it is harmless, but a large specimen can deliver a locally painful bite if carelessly handled. Adults have a body length of 2.2 to 2.8cm and a leg span of 7 to 12cm (females are typically the larger of two the sexes).
Female Banana Spiders carry their egg sac, containing about 200 eggs, under their body. A sac contains about 200 eggs. The spiderlings hatch and disperse by ballooning. Another spider that occurs in bananas is Torania from West Africa.