Ants in the City: Found and chosen families, too

As the holiday season approaches, it’s common for families to come together. Some will gather with their family of origin, some with step-families, godparents, or in polyamorous units, and many from marginalized groups including veteran, patient, queer, trans, and nonbinary communities, will gather with found and chosen families. Ants in the city too, of course, dine with a diverse association of sisters and both close, and not so close, associates.

Living alongside the ants are hosts of other insects and arthropods, including aphids, beetles, caterpillars, crickets, cockroaches, flies, mites, silverfish, spiders, springtails, and treehoppers. These myrmecophiles exhibit many kinds of interactions with the ants, with relationships ranging from neighbors to parasites, and both facultative and obligate mutualisms. When we’ve followed Needle Ants running between buildings and around their nest on campus at Providence College, there can be at least as many bright red Loricate Staphylinid Beetles on the trails as there are ants, and we’ve often wondered what their relationship is to the ants they run beside. Some of the fascinating behaviors exhibited by myrmecophiles include chemical deception to evade detection by ants, morphological mimicry to blend in, dispersal by riding along with flying queens, and vibrational communication to solicit feeding through trophallaxis from ant workers. There are vertebrate myrmecophiles as well, including tadpoles which hatch and develop within leaf-cutting ant nests, antbirds that take advantage of insect prey escaping from foraging ant swarms, and both snakes and lizards that lay their eggs within ant nests. When author and myrmecophile expert Dr. Christina Kwapich speaks of the ant guests, she centers their nest architecture as one of the jumping-off points for the success of this strategy.

Ant nests provide buffered and stable microhabitats, access to food stores and potential prey, a spatially stratified internal organization, and are often aggressively guarded. For a myrmecophile that can be accepted by the society, it can be an enticingly safe (and sometimes, tasty) space. Our own dwelling places offer many of the same advantages, and while we’re familiar with some of the more common “pest” critters that dwell within our homes, how many other associates are we sharing our homes with? A public science project started by Rob Dunn is trying to answer this question by analyzing observations uploaded to the iNaturalist community biodiversity platform. In the world’s largest study of indoor organisms, more than 7,300 animal species were documented by almost 5,000 observers worldwide, including 80 species of spiders, ants, flies, and other critters living in our homes in Rhode Island. It’s common, whether when thinking about myrmecophiles or our own nestmates, to want to assign a value to these associations, identifying whether they are the good kind of mutualism or potentially costly. As part of an ongoing effort to decolonize myrmecology though, we might try to look past this binary and instead also recognize the potential for plesiobiotic interactions; the association of two or more species without material interdependence, in short, just hanging out with each other. Estefanía Vélez, a librarian with the New York Public Library who compiled an online list of literature celebrating families of choice, wrote that “unconditional love comes in all forms, and so do families.” It’s not clear if the ants love all of their thousands of guests, but colonies are definitely homes to diverse families, and our society is too. •

Illustration by Danika Valentine. Follow Dr. Jane and her research lab on Instagram @antlabpvd or on the web at lovetheants.org