SMELL — FIELDWORK AND EXPERIMENTS IO7 



rotten. This can be shown by keeping a tame dormouse or 

 squirrel and offering it nuts, some of which must be known 

 to have rotted kernels. The rodent will sniff the nut and 

 will invariably discard one which has gone bad. I have 

 never known any of my pet squirrels or dormice to bother 

 nibbling a nut unless it was a sound one. 



Hedgehogs are very discriminating in their sense of smell 

 and will ignore ground beetles which have an unpleasant 

 odour, while eating greedily those beetles and other insects 

 which have not. Carrion, too, will be scented from afar by 

 hedgehogs as will a broken bird's-egg or the milk from the 

 leaking udder of a cow. Incidentally, hedgehogs do not suck 

 the cows' teats, they simply detect the smell of milk that 

 may at times be dribbUng out on to the ground in a meadow. 



I have already made reference to the scents from glands 

 in their own bodies that are used to convey "messages" and 

 mark territories by many mammals. Deer are among these, 

 and in this country the Roe Deer will, in the rutting season, 

 give off scent from glands in its forehead. At the same time, 

 the buck will rub itself against herbage and thrash to and 

 fro with its antlers, thus dispersing the scent. 



Many other mammals "set" scent for marking out their 

 own territories — badgers, mongooses, lemurs, all do this; 

 and, of course, our domestic dogs leave trails by urination 

 and depositing faeces. These are nearly always attended to 

 by other dogs which, in turn, leave their marks in similar 

 fashion. 



In captivity, the marking out of territory can be easily 

 observed by anyone who keeps a bush-baby as a pet. As 

 soon as it is put into a new cage it will mark the limits of 

 the cage by urinating in the corners of it. This is not only 

 a territorial affair, it is also connected with breeding, for I 

 have noticed that breeding seldom takes place unless a cage 

 has been well and truly "marked". 



The scents given off by female mammals when in season 

 are naturally a very necessary preliminary to mating. Such 

 scent is powerful and persistent; and any dog-owner will 

 know full well the distances from which amorous male dogs 

 will come in order to seek out a bitch on heat. This will prove 

 a great nuisance to owners of dogs and bitches alike, unless 



