Although we normally associate nature with the outdoors, there are ample opportunities to study wildlife within our homes, as a recent visitor to our bathroom has proven.
I first became aware of the creature late one night, when I detected movement near the bath plughole shortly after turning the light on. On closer inspection, I was intrigued to see a streamlined metallic insect the length of my fingernail slink its way into a darker area of the bath with a strange sinuous movement. There was an otherworldliness about the creature as it explored the bath, its long antennae feeling the plastic surface ahead of it and its three distinctive tails streaming out to the rear. Whenever it shifted position its form of movement seemed more akin to a water-dwelling insect than one from the terrestrial sphere.
Although I recognised the insect as a silverfish – having been shown several by my mother when I was a child – I realised I knew very little about this new denizen of our bathroom. A little research, however, soon revealed the world of the silverfish to be particularly fascinating.
I was surprised to learn that the silverfish is considered by many entomologists to be a ‘living fossil’ of very ancient evolutionary lineage, that has changed little over tens of millions of years. Indeed, it is thought that insects very similar to silverfish crawled around the feet of dinosaurs. Furthermore, silverfish may have had a more fundamental influence on the insect world as it has been suggested that primitive animals very similar to modern-day silverfish may have given rise to the great variety of insects that inhabit the earth today.
Although they do not live exclusively in and around human habitation, silverfish have been especially effective at exploiting our world, partly because they are able to thrive on the smallest scraps of food. They are also able to digest cellulose and can therefore derive energy from books and documents and have even been known to gnaw through stored stamp collections! The occurrence of silverfish in bathrooms is very common as they prefer a high humidity and access to water. They also occur regularly in kitchens, where they readily find starchy foods such as bread scraps and flour.
Surprisingly, silverfish can even be readily kept in captivity, where they can live for over five years – a very long time for an insect the size of a fingernail.