Drunk and sober Ants behavior with each other

19th century biologist Sir John Lubbock experimented on ants by getting them drunk. He discovered that sober ants would carry their drunken ant comrades back to their nest, if they were from the same colony – but they would throw drunk strangers into the ditch.

THE anthropoid apes no doubt approach nearer to man in bodily structure than do any other animals; but when we consider the habits of ants, their social organization, their large communities, elaborate habitations, their roadways, their possession of domestic animals, and even in some cases of slaves, it must be admitted that they have a fair claim to rank next to man in the scale of intelligence. They present, moreover, not only a most interesting but also a very extensive field of study. In this country we have nearly thirty species; but ants become more numerous, in species as well as individuals, in warmer countries, and more than seven hundred kinds are known. Even this large number certainly is far short of those actually in existence.

ants do not recover from chloroform, and these ants were therefore to all intents and purposes dead, we should not expect that much difference would be made between friends and strangers. I therefore tried the same experiment, only, instead of chloroforming the ants, I made them intoxicated. This was a rather more difficult experiment. No ant would voluntarily degrade herself by getting drunk, and it was not easy in all cases to hit off the requisite degree of this compulsory intoxication. In all cases they were made quite drunk, so that they lay helplessly on their backs. The sober ants seemed much puzzled at finding their friends in this helpless and discreditable condition. They took them up and carried them about for a while in a sort of aimless way, as if they did not know what to do with their drunkards, any more than we do. Ultimately, however, the results were as follows: The ants removed twenty-five friends and thirty strangers. Of the friends, twenty were carried into the nest, where no doubt they slept off the effect of the spirit—at least, we saw no more of them—and five were thrown into the water. Of the strangers, on the contrary, twenty-four were thrown into the water; only six were taken into the nest, and four of these were shortly afterward brought out again and thrown away.

The difference in the treatment of friends and strangers was, therefore, most marked.

Dead ants, I may add, are always brought out of the nest, and I have more than once found a little heap on one spot, giving it almost the appearance of a burial-ground.