434 USE OF MAN'S INSTRUMENTS. 



orang and chimpanzee open doors in the same way that 

 man does, even using a ~key, as in the case of a certain 

 chimpanzee (Houzeau). One orang-utan opened a padlock, 

 using a stick as a key, or more properly a lever (Houzeau), 

 and others open other kinds of locks, including those of doors 

 (Pierquin). A certain retriever had a knack of forcing 

 shutters and opening doors, so as to effect his escape when 

 imprisoned. A horse was troublesome from its ability to 

 open its stable door. A cow ' was in the habit of lifting the 

 latch with her horn, and then pushing the gate open ; ' 

 while other cows opened a byre door by ' inserting the tip 

 of a horn into the finger hole, lifting the latch, and then 

 drawing the door towards them ; * so that we have, even in 

 the same species, sometimes pulling, sometimes pushing, as 

 circumstances require. Even an ass was sagacious enough 

 to open every gate about a house (Wood). In some cases 

 the 'trap-doors' of spiders' nests in the South of Europe 

 6 have a handle or flap attached .... for more convenient 

 use of the spider ' (Moggridge), probably in holding them 

 down against entrants; for beetles lift up or open such 

 hinged doors, and so gain access to the nests of a New 

 Zealand species (Gillies). 



While, however, it is far from uncommon for cats, dogs, 

 horses, ponies, donkeys, or cows to open the doors of houses, 

 rooms, stables, or byres, or the gates of gardens, paddocks, 

 or poultry yards, it is not at all common for them to shut 

 them. But this is sometimes done when the animal has a 

 sufficient motive. Usually its object is simply to gain access 

 or egress. But occasionally an astute animal thinks it 

 desirable or necessary to barricade out of a tempting pad- 

 dock a hated rival, or to conceal the evidences of its trans- 

 gression of its master's rules ; or it may be that it shuts it 

 because it knows the door or gate is usually, and should be, 

 shut when not in use. Thus a gentleman, who has been a 

 great traveller and a keen observer of the habits of wild 

 and domestic animals, and is now a proprietor-farmer in one 

 of the western islands of Scotland, told me of a pony of his 

 own that both opens and shuts field-gates by means of its 

 teeth or otherwise, the shutting or closing being a com- 



