The many names of the woodlouse
You’re probably familiar with the woodlouse, but (unless they happen to be your field of study), you probably haven’t given them a great deal of thought lately. The more biologically-minded among you may throw around the Latin term isopoda for the order, and oniscus or armadillidium for the two common varieties, but to most of us the ‘small terrestrial crustacean with a greyish segmented body and seven pairs of legs, living in damp habitats’ is simply a woodlouse – and the variety that is able to roll up into a ball when threatened, a pill woodlouse. But this innocuous bug has attracted quite a few unusual alternative names over the years, which give an insight to the colourful elements of regional English.
Robin Goodfellow’s louse
Let’s start with my favourite. It may be obsolete, and was always rare, but Robin Goodfellow’s louse has been found as a term for the woodlouse in the mid-16th century. As for Robin Goodfellow, he was a mischievous sprite or goblin believed to haunt the countryside; an account of his purported activities is included by Shakespeare in A Midsummer Night’s Dream, where his exploits include leading travellers astray in the dark, interfering with the churning of butter, and playing practical jokes on women.
Quite why Robin Goodfellow would have an interest in woodlice is unclear, but a dialect term from the 19th century continues the tradition of goblins’ fondness for them: hob-thrush louse, based on hob-thrush as another name for a goblin. Similarly, the earlier thurse-louse comes from thurse, ‘goblin or hobgoblin’.
Various names for the woodlouse are constructed from the combinations of lock and chest, and though the origin is uncertain, it has been suggested that this refers to the woodlouse’s ability to roll itself up tightly – that is, to lock its chest. Lockchest and lockchester are both attested in Medieval English, and continued into the 20th century in some regional Englishes, while it has been suggested that the 16th-century cheslock is a reversed equivalent. As A.S. Palmer wrote in his 1904 work Folk and their Word-lore, it ‘long survived in Oxfordshire in the form of lockchester and lockchest’. An alternative theory has been put forward for lockchest, that it may be an alteration of the classical Latin locusta, denoting a kind of crustacean, perhaps a lobster.
Similar to lockchest, it appears that lugdor is a combination of lock and door. A door isn’t as obvious an element in the woodlouse’s ‘locking’ as a chest, and perhaps that is why dor has also been submitted as a possible element in lugdor’s etymology. Dor refers to ‘an insect that flies with a loud humming noise’ – that is, it has an entomological use, but usually for a different type of insect.
Various small terrestrial invertebrates with many legs could be known as palmer-worms – including woodlice, caterpillars, centipedes, and millipedes. This relates to the sense of palmer meaning ‘pilgrim’, and may have developed because (as a 1608 account explains) these sorts of creatures ‘have no certain place of abode, nor yet cannot tell where to find their food, but like unto superstitious Pilgrims, do wander and stray hither and thither’.
There’s no obvious connection between monkeys and woodlice – but monkey pea is found as a term for a woodlouse in the late 17th century and survived for some time in British regional use. A potentially related, though long obsolete, option is monk’s peason. The addition of pea is (like pill) presumably with reference to the shape of the insect when it is curled up – and also appears in pea-bug.
A more obvious animal connection is the armadillo, reflected in the Latin name of the pill woodlouse, armadillidium. Both creatures have a protective, ridged body, and the woodlouse in some ways resembles a miniature armadillo – which gets its name from the Spanish armado, ‘armed one’.
It’s the turn of swine next: various historical names for the woodlouse riff on a connection with pigs. Hog-louse and swine-louse crop up in the 16th century, with timber-sow in the 17th and sow-bug found by the 18th century; hog-beetle was another rare option. This is also seen in other languages – for instance, the Spanish cochinilla, ‘woodlouse’, is the diminutive of cochina, ‘sow’.
The pig theme continues with the obsolete and rare term porcelet, found in the late 16th century. It is probably a shortened version of porcelet Saint-Antoine, the French for ‘piglet of St Anthony’, apparently alluding to the piglet conventionally associated with St Anthony; the allusion (as the OED notes) is perhaps based on the unrealistically small size of the piglet in some of the depictions of the saint.
Still in use in Scotland, Australia, and New Zealand, slater is a term for a woodlouse that dates back to the 17th century (found in the earliest instances as sclater). As with the armadillo reference, slater presumably comes from the ridged nature of the backs of woodlice looking like slates.
One of the most recent additions to the pantheon of woodlouse nomenclature is roly-poly bug which, as with its older cousin lockchest, relates to the pill woodlouse’s ability to roll into a ball. Still a colloquial term and chiefly used in North America, roly-poly bug can also be applied to similar invertebrates.