THE ANIMAL COMMUNITY 51 



clothed with plants, some of which are different from those of 

 the surrounding pasture. This ant, itself forming highly 

 organised colonies, is the centre of a closely-knit community 

 of other animals. You may find green woodpeckers digging 

 great holes in the ant-hills, in order to secure the ants and their 

 pupae. If you run up quickly to one of these places, from which 

 a woodpecker has been disturbed, you may find that a robber 

 ant {Myrmica scabrinodis) has seized the opportunity to carry 

 off one of the pupae left behind by the yellow ants in their 

 flight. The latter with unending labour keep building up 

 the hills with new soil, and on this soil there grows a special 

 set of plants. Wild thyme {Thymus serpylhim) is particularly 

 common there, and its flowers attract the favourable notice 

 of a red-tailed bumble-bee (Bombus lapidarius) which visits 

 them to gather nectar. Another animal visits these ant-hills 

 for a different purpose : rabbits, in common with many other 

 mammals, have the peculiar habit of depositing their dung in 

 particular spots, often on some low hummock or tree-stump. 

 They also use ant-hills for this purpose, and thus provide 

 humus which counteracts to some extent the eroding effects 

 of the woodpeckers. It is interesting now to find that wild 

 thyme is detested by rabbits as a food,^^^ which fact perhaps 

 explains its prevalence on the ant-hills. There is a moth 

 {Pempelia subornatella) whose larvae make silken tubes among 

 the roots of wild thyme on such ant-hills ; then there is a 

 great army of hangers-on, guests, and parasites in the nests 

 themselves ; and so the story could be continued indefinitely. 

 But even this slight sketch enables one to get some idea of 

 the complexity of animal interrelations in a small area. 



2. One might leave the ants and follow out the effects of 

 the rabbits elsewhere. There are dor-beetles (Geotrupes) 

 which dig holes sometimes as much as four feet deep, in wliich 

 they store pellets of rabbit- dung for their own private use. 

 Rabbits themselves have far-reaching effects upon vegetation, 

 and in many parts of England they are one of the mqst im- 

 portant factors controlling the nature and direction of ecological 

 succession in plant communities, owing to the fact that they 

 have a special scale of preferences as to food, and eat down 



