Ants — Part 1

(Super-family Formicoidea.)

All of the true ants belong to this group. They are all very characteristic in appearance and there are very few other insects which can be mistaken for them, except possibly the so-called cow-ants, or velvet ants, of the family Mutillidae (super-family Vespoidea), or the so-called white ants, which be long to an entirely different order and which really should not be called ants, if popular names are to coincide at all with scientific classification. The true ants, however, as shown in the synoptic table, are readily distinguished from all other Hymenoptera, aside from their general and more characteristic appearance, by the one or two swellings on the petiole of the abdomen.

We have seen with the bees and with the wasps that while some species are social and live in communities, others are solitary in their habits. With the ants, however, it is different; all species live in communities and are social insects. Social life with certain of the ants is carried to the greatest extreme known in nature. The differentiation into different castes or forms of individuals of the same species is carried to a much higher extent than with the bees and the wasps. We have seen, with the bumblebees, the beginning of a separation into two classes of workers, that is to say, there are large workers and small workers which have different functions in the community. With the ants this becomes almost the rule and when we consider all ants we find that there may be eight distinct castes, not all in the same individual species, though five may occur in the same species. There are not only the ordinary winged males and the ordinary winged females, the large workers and the small workers (workers major and workers minor, as they are termed), but with certain species there is a well developed and well adapted caste which does the principal fighting for the community and which is known as the soldier. The workers, as with the bees, are simply infertile and undeveloped females. They never have wings. The true females have wings, but after the nuptial flight they are discarded and only at certain times in the year are winged individuals seen in an ant community. The true workers, when examined as to their internal anatomy, seem to differ principally from the true females in that they lack the receptaculum seminis. There are, however, with certain ants forms which never have wings and which in the female sex possesses a receptaculum seminis, and there are corresponding wingless males, that is, males which never develop wings. These are, then, sexually competent males and females, neither of which ever develop wings. This adds two more structural forms to the possible number of forms in a community, and they are called ergatoids. This is a term which will come more frequently into use and should be mentioned. It applies to both sexes, but the females are said to be ergatogynous and the males are said to be ergatandrous. The eighth possible form occurs exceptionally and seems to be intermediate between female and worker.

The community life of ants and their industry, thrift and supposed foresight have been the subject of observation and comment since the earliest times. The biblical references are familiar to all and the old ideas are well formulated in part in La Fontaine's charming fable of the Grasshopper and the Ant. Milton, Prior and many other poets have sung praises of the ant, and it is safe to use the trite expression and say that it is "fabled in song and story." In "The Royal Dream Book," an English north-country chapbook, it is said that "to dream of ants denotes that you will live in a great town or city, or in a large family, and that you will be industrious, happy, well-married and have a large family."

The ants form a very large group. More than two thousand species have been described. Sharp estimates that there are probably five thousand species in existence. There is a marked uniformity of structure as well as of habits in this great group and the systematic workers have so far made only eight families, of which the Camponotidae, or common stingless ants, and the Myrmicidae, or stinging ants, are the most familiar examples to persons living in the more northern United States. Representatives of the curious ants of the family Poneridae occur in the Southern States.