Turn a stone over and you may see tens of bugs crawling, running and leaping around. Although many of them are too small for people to notice, bugs live everywhere around us and are animals just like fish, birds, frogs, lizards and mammals. Bugs with legs belong to a large group of animals called the Arthropods. This group includes insects, arachnids, centipedes, millipedes and crustaceans. It is easy to tell each group apart just by counting their legs and looking at the shape of their body. Insects always have six legs and a body divided in three main parts. Arachnids always have eight legs and a body in one part (daddy long legs) or two parts (spiders).  Centipedes have a long segmented body with 15 to 191 pairs of legs, as one pair of legs for each body segment. Millipedes have two pairs of legs per body segment and may have between 6 and 175 segments; that means that a single millipede can have up to 700 legs!   Crustaceans usually live in fresh water and in the sea but some of them live on land. Crustaceans can be recognised by their segmented body and their many mouthparts. Arthropods never have a skeleton inside their body like we do; instead, they have a strong carapace called an exoskeleton. When an arthropod grows too large for its exoskeleton, it will just shed it and grow a new, larger one.

Devil’s Coach Horse
Dara daol Ocypus olens
The Devil’s Coach Horse is one of the largest beetles in Ireland, measuring 25 to 30mm long. It can be found between April and October, usually under stones and in the leaf litter of humid grasslands and forests. When disturbed, the Devil’s Coach Horse tries to scare its opponent by raising the rear end of its bluish-black body, in a position similar to a scorpion ready to sting. Devil’s Coach Horses are mainly predators: they use their large mandibles to catch and devour bugs, worms and slugs. In Ireland it was believed that the Devil could take the shape of a Devil’s Coach Horse to travel unnoticed through the country, and seeing this beetle was considered to be a very bad omen!

Stone Centiped
Céadchosach Lithobius forficatus
The Stone Centipede has a long reddish-brown body, and 15 pairs of legs when adult. Stone Centipedes do not like direct sunlight and they spend most of their life under stones and logs where they hunt small bugs and worms. To catch their prey, centipedes use a pair of legs which are modified into two large venom claws located under the head. While Stone Centipedes can’t hurt you with their claws, their cousins from the tropics can reach 30cm long and are well-known for inflicting very painful or even life-threatening stings. In parts of Asia people have erected temples to honour these fierce predators and to ask centipedes for good fortune through the year. 

Common Darter
Snáthaid Mhór Sympetrum striolatum
The Common Darter is one of the most abundant dragonflies in Ireland. It is about 40mm long, with four large wings and a dark grey, green or red body. The Common Darter can be seen between May and November, flying rapidly in search of small prey usually over rivers, lakes and ponds. Dragonflies spend most of their lifetime in the form of aquatic larvae called naiads. Naiads do not have wings, but they do have six legs like adult dragonflies and have gills to be able to breath under water. After three to five years in the water, naiads climb on plants to get above the surface of the water and metamorphose into adult dragonflies.