62 The Naturalist in Nicaragua 
the carbolic acid had killed. A few days afterwards, when 
I visited the locality again, I found both the old burrows and 
the new one entirely deserted, and I thought they had died 
off; but subsequent events convinced me that the survivors 
had only moved away to a greater distance. 
It was fully twelve months before my garden was again 
invaded. I had thena number of rose-trees and also cabbages 
growing, which the ants seemed to prefer to everything else. 
The rose-trees were soon defoliated, and great havoc was 
made amongst the cabbages. I followed them to their nest, 
and found it about two hundred yards from the one of the 
year before. I poured down the burrows, as before, several 
buckets of water with carbolic acid. The water is required 
to carry the acid down to the lowest chambers. The ants, 
as before, were at once withdrawn from my garden; and 
two days afterwards, on visiting the place, I found all the 
survivors at work on one track that led directly to the old 
nest of the year before, where they were busily employed 
making fresh excavations. Many were bringing along pieces 
of the ant-food from the old to the new nests; others carried 
the undeveloped white pupz and larve. It was a wholesale 
and entire migration; and the next day the formicarium 
down which I had last poured the carbolic acid was entirely 
deserted. I afterwards found that when much disturbed, 
and many of the ants destroyed, the survivors migrate to 
a new locality. I do not doubt that some of the leading 
minds in this formicarium recollected the nest of the year 
before, and directed the migration to it. 
Don Francisco Velasquez informed me, in 1870, that he 
had a powder which made the ants mad, so that they bit and 
destroyed each other. He gave me a little of it, and it 
proved to be corrosive sublimate. I made several trials of 
it, and found it most efficacious in turning a large column of 
the ants. - A little of it sprinkled across one of their paths in 
dry weather has a most surprising effect. As soon as one 
of the ants touches the white powder, it commences to run 
about wildly, and to attack any other ant it comes across. 
In a couple of hours, round balls of the ants will be found all 
biting each other; and numerous individuals will be seen 
bitten completely in two, whilst others have lost some of 
their legs or antenne. News of the commotion is carried to 
