SCIENTIFICALLY, this tiny arachnid goes by the name of Theridion grallator - but it takes little imagination to see how it got its more popular name: the happy-face spider. Found only in rainforests in the Hawaiian islands, the spiders have a vast range of patterns and colours on their abdomens - yet all come from the same species. The amazing diversity is due to genetic variations, although the patterns may also change depending on diet. The patterns may have developed as a way of confusing predators. The moment it takes an aggressor to work out whether the spider is prey or not provides a vital chance of escape.However, the species, which was discovered in 1973, is now under threat from the introduction of non-native animals to the islands. The most common form - or 'morph - is plain yellow and has no smile. But other variations are plentiful - the 'red front morph pictured here with a cluster of her eggs is the second-most common. The spiders are 5mm (less than a quarter of an inch) long and live alone on the underside of leaves - except during their mating season and for the first 40 to 100 days of spiderlings lives, when they are still too young to fend for themselves. Daily Mail