250 BRITISH ANTS. 



bits of stick, leaves, dried grass, or any other vegetable refuse, 

 small shells, pebbles, etc. 



In oak-woods they are chiefly composed of oak-twigs ; at Nethy 

 Bridge I have seen a nest formed entirely of Juniper leaves and 

 twigs, at Weybridge of bracken, grass, and birch, and in Parkhurst 

 Forest I found a small nest chiefly composed of small pebbles, which 

 gave it a rather strange appearance the ants must have ex- 

 perienced considerable difficulty in carrying some of the larger 

 stones, and placing them in position on the top of the hillock 81 . 



In Northumberland and Scotland these ants collect large quanti- 

 ties of yellow resin " ant-amber " from the fir trees ; I have 

 seen nests full of it, and Latreille states that in Sweden the inhabi- 

 tants gather the resin of Juniper trees accumulated by F. rufa in 

 its nests and burn it to purify the air 4 . 



Under the hillock is a large central chamber, which is connected 

 by galleries with other underground chambers and other parts of the 

 nest. Numerous openings all over the structure form entrances to 

 the nest ; these are closed by the ants at night with twigs, etc., laid 

 across each other, and sentinels are always stationed at these 

 entrances. The habit peculiar to this ant and its allies of building 

 hillocks shows their descent from a more ancient arctic life, as the 

 heaping up of these mounds better attracts the rays of the sun 

 and also concentrates the warmth in the nest. 



Bignell in describing a large nest near Plymouth which he had 

 known for ten years, and which he stated would measure forty feet 

 in circumference at its base, writes : " The extreme west side of 

 it has been given up in consequence of receiving the beat of the 

 weather " 58 but the real reason for this was that, as we have 

 before shown, ants prefer to face the east, and they would continue 

 to build towards the east to obtain the most benefit from the sun. 



The height and size of these hillocks varies according to the age 

 of the nest, their situation and whether they have been disturbed 

 or not. Latreille 4 , Daniell 19 , and Bignell 41 record nests three feet 

 high, Farren-White says he has found them full forty feet in circum- 

 ference 53 , Forel gives one metre high and two metres in diameter, 

 and Buchanan -White mentions nests four feet in height and twenty- 

 five feet in circumference in Scotland 34 , but I have seen some 

 narrow cone-shaped nests quite five feet high at Aviemore. 



Joy records rufa nests situated in very thick undergrowth near 

 Bradfield. He writes : " The wood had been cleared two years 

 before and small fir trees had been planted. It had not however 

 been ' grubbed ' and the stumps of the trees and briars were growing 

 freely. It seemed rather a hopeless place to look for nests, but 

 the keeper pointed out to me that when a nest was placed in thick 

 undergrowth, the latter was evidently well nourished, as it was 

 taller than the surrounding herbage and of a darker green. After 

 this I had no difficulty in locating nests from some yards' distance, 



