Several months ago I went to our pantry to retrieve a box of raisin cereal. To my horror it was filled with hundreds perhaps thousands of little black ants with a line of them leading to a tiny hole in the wall. These were crazy ants or longhorn crazy ants (Paratrechina longicornis), named for their seemingly random, rapid and jerky foraging activities.
They are brownish-black, about three millimeters in length, with extremely long legs and antenna, and have a blue iridescence. As I came to find out, they are an invasive species in Florida, considered to be a minor picnic pest; they can also be a major house pest and are extremely difficult to eradicate or control. No exterminator would guarantee that they could get rid of them. Most promised that they couldn’t.
I have observed these in and around my home in Central Florida and here are a few reasons they are so difficult to keep out of your house (and effective as a species).
- They can make a nest almost anywhere. I have found them under leaves, in soil, in the crotch of a tree, in a house gutter, on a palm leaf, in the wall of a house, inside a tiny metal pipe, and exposed on the bottom side of an elevated fire pit. I recently discovered a nest within the nest of Florida carpenter ants (Camponatus floridanus). There didn’t seem to be any symbiotic relationship, and the carpenter ants seemingly ignored their presence.
- They have multiple nesting sites within a single colony. I have seen companion nests over 75 feet away from other nests, yet the ants can be observed traveling in a line from nest site to nest site even at that distance. They will have multiple queens in this single colony, as many as 40.
- These nests also appear to be temporary, and I often observed them moving the entire nest in a mad dash to another location. They workers held the eggs and pupa high in the air as they scurried single file to a new nesting site. I have not been able to determine why they do this. Perhaps the nest was destroyed, overpopulated or some other reason. This activity seems more commonplace in the warmer months.
- They run away from a disturbed nest site and hide until the danger has passed. When you disturb a nest many ant species will scramble to the defense and move larva and pupae deeper in the nest. One day I found a Paratrechina longicornis nest in the crotch of a tree, and once disturbed, the worker ants fled the nest in every direction carrying the young. Most of them went a few feet away and hid deep in the crevices of the bark. Later, after the danger was past, they returned to the nest with the pupae. I can imagine this behavior apparently makes it harder to destroy the nest by digging through it.
- These omnivores forage for almost anything that might provide a food source. They will eat seeds, sugars, other insects, human food scraps, fruit, honeydew from homopteran such as mealy bugs, and apparently raisin cereal. I have noticed, though, that their taste varies with the season of the year. This makes baiting difficult. These also forage far from their nest which makes nest location difficult.
To purchase prints or license these photos and others, visit my gallery.