SCORPIONS 73 



Indeed, Sergent (1947) has shown that the negative reactions to 

 hght of Androctonus australis, Buthus occitanus and Scorpio maurus 

 are less marked than are their positively thigmotactic responses, so 

 it is probable that their nocturnal behaviour has an ecological 

 rather than a physiological significance. Scorpions are essentially 

 inhabitants of warm climates and become sluggish in cold weather, 

 although they can withstand freezing for several weeks (Vachon, 

 1953). 



Their lives are comparatively simple: not even the most primi- 

 tive forms of animal association are known and all species lead 

 strictly individual lives and usually either avoid each other or 

 fight to the death. The fact that aggregations are sometimes found 

 in certain areas is not due to social instincts — these are con- 

 spicuously absent — but to the fact that the young do not scatter far 

 from their place of birth. Fabre's (1907) claim that when two are 

 found beneath the same stone they are either mating or else one is 

 devouring the other may be an exaggerated generalisation, but is 

 probably not entirely without foundation. 



Some scorpions (e.g. Euscorpius spp.) normally frequent damp 

 places, others (e.g. Pandinus, Palamnaeus spp.) are forest dwellers 

 whilst perhaps the best known (e.g. Scorpio^ Buthus, Androctonus 

 spp.) are inhabitants of dry and desert regions. Most scorpions do 

 not drink, but moisture loving species such as Euscorpius italicus 

 are sensitive both to drought and to excessive moisture (Bott, 1951; 

 Cloudsley-Thompson, 1951). Schultze (1927) however found that 

 the large Philippine forest scorpion Palamnaeus longimanus had to 

 be given a certain amount of water every day, and it was astonish- 

 ing what large amounts of water this creature would drink. The 

 scorpion would take up drops of water from grooves in bark, 

 drops scattered on its body or sip with its mandibles water that had 

 accumulated between the chelae — that is, it would move the latter 

 close to the mandibles 'in the way a man holds a glass in his hand 

 and brings it towards his mouth'. At the same time, Sergent (1946) 

 has shown that although A. australis is a species particularly adap- 

 ted to a dry climate, it does not avoid water and can resist pro- 

 longed immersion (31% survived 24 hours), while S. maurus can 

 survive immersion for up to 48 hours (67%). 



From his interesting studies Vachon (1952, 1953) has recently 



