96 VOYAGE UP THE TAPAJOS. Chap. II. 



the insect pests of other parts, mosquitoes, sand-flies, 

 Motucas and piums ; but the formiga de fogo is per- 

 haps a greater plague than all the others put toge- 

 ther. It is found only on sandy soils in open places, 

 and seems to thrive most in the neighbourhood of houses 

 and weedy villages, such as Aveyros : it does not occur 

 at all in the shades of the forest. I noticed it in most 

 places on the banks of the Amazons, but the species is 

 not very common on the main river, and its presence is 

 there scarcely noticed, because it does not attack man, 

 and the sting is not so virulent as it is in the same spe- 

 cies on the banks of the Tapajos. Aveyros was deserted 

 a few years before my v^sit on account of this little tor- 

 mentor, and the inhabitants had only recently returned 

 to their houses, thinking its numbers had decreased. 

 It is a small species, of a shining reddish colour, not 

 oreatly differing from the common red stinging ant of 

 our own country (Myrmica rubra), except that the pain 

 and irritation caused by its sting are much greater. 

 The soil of the whole village is undermined by it : 

 the ground is perforated with the entrances to their 

 subterranean galleries, and a little sandy dome occurs 

 here and there, where the insects bring their young to 

 receive warmth near the surface. The houses are over- 

 run with them ; they dispute every fragment of food 

 with the inhabitants, and destroy clothing for the sake 

 of the starch. All eatables are obliged to be suspended 

 in baskets from the rafters, and the cords well soaked 

 with copaiiba balsam, which is the only means known of 

 preventing them from climbing. They seem to attack 

 persons out of sheer malice : if we stood for a few 



