32 the senses of animals 



Worms 



Among the lower animals, the earthworm is worthy of some 

 field study, because it is possible with a minimum amount of 

 time, trouble and apparatus to observe some of its behaviour 

 in its natural surroundings. Earthworms of all kinds are 

 burrowers by nature, but the Lob-worm {Lumbricus terrestris) 

 is the easiest one on which to base one's experiments. 



Every coarse-fisherman has at times to collect numbers of 

 these worms, and as I am myself a keen angler, I have on 

 countless occasions obtained dozens of these on warm and 

 preferably dewy nights. This is less hard work than digging 

 for them since it is always possible to find out whether they 

 are present in numbers under the surface of your lawn by 

 observing the characteristic worm "casts" which show them- 

 selves on any well-laid lawn so long as it has not been treated 

 with any "worm-killer" — a most reprehensible practice from 

 the naturalist's point of view ! 



I have already pointed out that earthworms are negatively 

 affected by light, and in spite of statements to the contrary, 

 I have found that moonless nights are better for capturing 

 earthworms. All one wants is a good electric torch, a deep 

 tin for the worms, and considerable agility and swiftness of 

 movement. 



On such nights as I have described the worms will come 

 out of their burrows — at times leaving the burrows com- 

 pletely — but usually lying out on the grass with the muscular 

 flat tip of their tails still in the mouths of the holes leading 

 to their burrows. 



Long ago I learned that to be successful in collecting 

 worms under these conditions I had to proceed with caution ; 

 otherwise my footfalls would set up vibrations in the ground 

 which would be instantly detected by the worms, which 

 would then vanish before I had time even to start to capture 

 them. I would walk stealthily round the margins of the lawn 

 to begin with, leaving the centre area until I had explored 

 the edges. I would switch on my torch and play it slowly 

 over the grass in front of me. Should a worm be seen lying 

 out away from its burrow a quick grab would usually secure 

 it; but it is very necessary to do this without much fuss or 



