WOODLICE 5 



surfaces, regain their weight by absorption of water through the 

 mouth. These experiments explain how woodUce which are known 

 to lose water in all but saturated air, can nevertheless survive in- 

 definitely in unsaturated air provided that a moist surface is 

 available (Edney, 1954). 



General behaviour 



In different parts of the countr}' there are many curious super- 

 stitions about woodlice. For example, in some places their presence 

 indoors is regarded as unlucky and any food on which they may 

 happen to wander is considered poisoned. On the other hand, in 

 certain other districts until very recently a few live woodlice 

 thrust down the throat of a cow^ were believed to have beneficial 

 effects and 'to promote the restoration of the cud'. No doubt this 

 is why in Shropshire and neighbouring counties woodlice or 

 slaters are sometimes referred to as * cud- worms'. At one time too, 

 woodlice were prescribed to be sw^allowed alive as a remedy for 

 scrofulous symptoms and for diseases of the liver and digestive 

 organs. It is surprising too how many local names have been 

 given to woodlice: Collinge (1935) listed no less than 65 rang- 

 ing from 'Bibble bugs' (Stafford), 'Cheese-pigs' (Berkshire) and 

 'Coffin- cutters' (Ireland) to 'Monkey peas' (Kent), 'Penny- 

 pigs' (Wales), 'Sink-lice' (Lancashire and Stafford) and 'Tiggy- 

 hogs' (Northamptonshire). In America they are known as 'Sow- 

 bugs'. 



Humidity is an environmental factor of prime importance, both 

 to woodlice and to myriapods, as they all lack a waterproof integu- 

 ment. Woodlice are ver\' sensitive to humidity gradients and ag- 

 gregate in areas of high humidity. The mechanism by which this 

 occurs is t^vo-fold: firstly, the animals show a decrease in activity 

 and speed in moist air and secondly they change direction more 

 frequently in damp places so that once they have arrived in a 

 moist situation they tend to remain there. This reaction to the 

 relative humidit\" of the air is also combined with avoidance of 

 light and a reaction that causes them to make contact wdth as 

 much of their surroundings as possible. The result of this is that 

 not only do the animals enter narrow crevices, but they bunch 

 together and consequently protect each other from evaporation. 



