44 THE SENSES OF ANIMALS 



To watch newts feeding in their normal surroundings is 

 difficult, because it is only by very good luck that you will 

 catch a glimpse of one doing so ; and this will be when a 

 surface insect is taken. As, however, newts must breathe 

 atmospheric air they have to rise to the surface at frequent 

 intervals to obtain it. When they do this they cause a ring 

 to form on the water somewhat similar to that made by a 

 "rising" fish, and this may be mistaken for the snapping up 

 of an insect on top of the water. Such faulty observations 

 will render any records useless. Newts in tanks are much 

 more reliable as indicators of feeding behaviour. 



Small earthworms are good food items to start with be- 

 cause they can be easily seen. A worm should be placed in 

 the tank about eight inches from where the newt is lying. 

 Unless the newt is too well fed, it will at once take notice and 

 will usually approach slowly, then with a swift dart it will 

 seize the worm. Repeat this experiment with the worm 

 farther and farther away from the newt and note the greatest 

 distance over which the newt will sight the moving worm. 



For more exacting tests use "bloodworms", which are the 

 larvae of certain gnats ; they can be bought at most good 

 aquarists' stores. They look like tiny, deep scarlet worms, 

 and though small they are active in their movements. The 

 best way to test sight with these larvae is to transfer your 

 newt to a large (24 X 12 X 8 inches) tank with nothing in 

 it except some clean water. Then place one bloodworm in 

 the tank as far from the newt as possible and watch. If the 

 newt is turned away from the place where the bloodworm is 

 wriggling, gently touch the newt near its head with a pencil. 

 This often turns it round without disturbing it too much. As 

 soon as it catches sight of the bloodworm, it will chase it, 

 and though it may not be able to catch it at once, it is the 

 distance from which the prey was spotted that is worthy of 

 note. The quickness with which a newt will respond to the 

 attraction of such a moving food item will surprise most 

 students who view it for the first time. 



To experiment with newts feeding on land it is, of course, 

 necessary to find one or two which are already in the terres- 

 trial state. They may be discovered from October to Feb- 

 ruary under logs of wood, old tin sheets, sacks and so on 



