Prenolepis imparis
In 3 days ~30% in a week ~50%
Prenolepis imparis, commonly known as the winter ant, false honey ant, or false honeypot ant, is a species of ant in the genus Prenolepis. The species is found in North America, from Canada to Mexico, nesting deep within the ground. Unusual among ants, Prenolepis imparis prefers lower temperatures, including near freezing, and is only active outside the nest during winter and early spring. Prenolepis imparis enters a hibernation-like state called aestivation during the summer.
P. imparis secretes an opaque white liquid from its abdomen as a defense against other ants, including Linepithema humile. The defensive secretions appear to be derived anatomically from the Dufour's gland and has been shown to contain a mixture of alkanes and alkenes including hexadecene, octadecene, tetradecene, octylcyclohexane, and hexadecane. Secretions from P. imparis have experimentally been shown to often kill L. humile workers. Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Great Smoky Mountains National Park | 🇺🇸 United States | |
| 2 | Shenandoah National Park | 🇺🇸 United States | |
| 3 | Congaree National Park | 🇺🇸 United States | |
| 4 | Sequoia and Kings Canyon National Parks | 🇺🇸 United States | |
| 5 | Yosemite National Park | 🇺🇸 United States |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Boston | 🇺🇸 United States | |
| 2 | Philadelphia | 🇺🇸 United States | |
| 3 | Washington | 🇺🇸 United States | |
| 4 | San Francisco | 🇺🇸 United States | |
| 5 | New York City | 🇺🇸 United States | |
| 6 | Toronto | 🇨🇦 Canada | |
| 7 | Sacramento | 🇺🇸 United States | |
| 8 | Minneapolis [Saint Paul] | 🇺🇸 United States | |
| 9 | Chicago | 🇺🇸 United States | |
| 10 | Detroit | 🇺🇸 United States |
With luck
About 10% of wildlife watchers report an American Winter Ant sighting in San Francisco on a given day, based on 881 verified sightings from GBIF citizen-science data. It is the 28th most-seen of the 737 insects we can rate there. Over three days the chance rises to about 30%, and over a week to about 50%, if each day is a fresh chance.
February and March
In those months about 20% of wildlife watchers report an American Winter Ant in San Francisco on a given day, against under 5% in July and August, the lowest months. Those are among San Francisco's wettest months, with about 85 mm of rain a month against almost none in July.
Between 1 and 4 pm
Across all the parks we cover, that three-hour window holds the most American Winter Ant sightings with a recorded time, and about 9 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
4th of 16
Of the 16 cities where we can rate American Winter Ant sightings, San Francisco ranks 4th at about 10%. The best odds are in Boston (United States, about 20%), Philadelphia (United States, about 10%) and Washington (United States, about 10%).
GBIF citizen-science records
It is estimated from how often the American Winter Ant is recorded against all the insects logged in San Francisco (881 verified sightings), calibrated against known sighting rates. Figures are rounded to the nearest 10% because citizen-science data supports honest approximations, not decimals, and months with records from fewer than five people show "—". How it works.
