Okay, so they respond to sound but theyвЂ™re not that smartвЂ¦ are they? Darwin rightly concluded that they were acutely aware of sound vibrations вЂ“ a mechanism that helps them escape from underground predators such as moles. When he placed them on his piano, in a pot of soil, they retreated underground as soon as a note was played. Charles Darwin discovered that while they donвЂ™t have ears, they still вЂhearвЂ™.

While earthworms are essentially one long digestive system, designed to break down organic material and release those nutrients back into the soil, theyвЂ™re also wonderfully, remarkably complex. ArenвЂ™t they just a wriggly tube with a mouth and a bottom? So, where possible, be careful when wielding your garden spade!Д®d Reschke Getty Images 5. The common earthworm may survive having its tail cut off below the saddle, as youвЂ™ll miss most of its major organs, but itвЂ™ll never quite return to its former glory. The easiest way to tell is to look for its saddle or clitellum, a fleshy ring around its middle that sits closer to its head end.

Well, to answer the question, you first need to know where the front end of an earthworm is. Is it really true you can chop an earthworm in two and both halves survive? The largest common earthworm ever recorded in the UK measured 40cm long and was discovered in an English vegetable patch. Oh, there have been some absolute whoppers. Despite their name, they actually only account for one in every 80 earthworms under our feet. Red and grey? I thought worms were pink?ДЄh yes, youвЂ™re thinking of the big, juicy вЂdeep burrowersвЂ™, like the common earthworm ( Lumbricus terrestris), who can tunnel down to a depth of three metres. Then thereвЂ™s вЂshallow burrowingвЂ™ worms, such as the grey worm ( Aporrectodea caliginosa), who dig no deeper than 30cm. The most numerous group in the UK are the reddish-brown вЂsurface dwellersвЂ™, such as tiger worms ( Eisenia fetida), who rummage around in decomposing leaves and other organic matter. There are actually thousands of different species around the world and Britain has 26 of its very own. So, an earthwormвЂ™s just an earthworm, right? Here's everything you need to know about earthworms. Have you ever stopped to give them much thought? It turns out they are really rather incredible, as Sally Coulthard is about to reveal.

Earthworm sally