European Fire Ants

Notice: European fire ants have been confirmed in a confined location within Sardis Park as shown by the red dot on the map below. For more information about this occurrence, please refer to the Frequently Asked Questions document attached at the bottom of this webpage.


What are European fire ants (EFA)?

European fire ants (Myrmica rubra), are small reddish brown ants. The workers are about a ½ cm long and queens are a little larger. These ants are only distantly related to the “true” fire ant species (red imported fire ant) found in the Southern U.S.A. and Latin America.

First recorded in BC in 2010, European fire ants are now found in many communities in the Lower Mainland and on Vancouver Island. They are known to exist in Chilliwack.

EFAs prefer moist environments, such as irrigated lawns and gardens on BC’s West Coast. Unlike ants with obvious mounded nests, EFA nests can be difficult to spot. Nests vary from a few hundred to a few thousand workers, usually with multiple egg-laying queens (20 queens per nest on average). Each nest consists of a series of popcorn-sized chambers along a vertical shaft, barely 15 cm wide and no more than 20 cm below ground. They are found in soil and mulch, lawns, moss, along roots, in decaying wood, under rocks or other debris.

Why are they a problem?

This aggressive, swarming ant can deliver a painful sting when disturbed, rarely leading to an allergic reaction requiring medical treatment. Colonies can reach densities of four nests per square metre, rendering gardens, lawns and parks unusable for normal activities because of repeated stings. European fire ants also displace benificial native ants.

How do they spread?

The most likely way is through the movement of infested garden material such as soil, mulch and plants. Once established, colonies spread naturally through "colony budding,” where one or more queens and a group of workers leave to establish a new colony, often less than a metre from the original. Please see the procedure for disposal of yard material containing European Fire Ants attached at the bottom of this page.

What you should know

European Fire Ants aggressively defend their territory and sting humans and pets that move slowly or rest near a nest. When in an area where they are suspected, keep moving! Wear rubber boots with pants tucked in to deter ants from crawling up your legs. If you come in contact with the ants, swipe them away and do not attempt to crush them. This will only provoke them to sting.

Reaction to a sting varies from one person to another. The ant injects venom under the skin that initially burns (30 minutes to 2 hours) then itches for a few days to a week. Stings usually result in an inflamed red area from 1-4 inches in diameter, sometimes with a raised white area in the center. If safe to do so, you may want to collect some ants in a sealed container for identification purposes. Please note there are many species of ants in our region, including red ones. Do not assume that any red ant you see is a European fire ant. If you suspect you have been stung by EFAs on City property (eg. a park), please notify the City and provide as much detail as possible about the incident and specific location.

If you experience a stronger reaction than minor swelling, redness, discomfort or itching, call HealthLinkBC at 8-1-1 for symptom advice, open 24 hours-a-day. An extreme allergic (anaphylactic) reaction can be life-threatening and requires emergency care. To date, there have been no reported cases of anaphylaxis associated with European fire ant stings.

What control options are available?

Prevention is the best option. To help prevent the spread of the EFA, avoid sharing soil, mulch or plants with others. Please do not dump yard waste or garden materials. Check newly purchased plants and soil before introducing them to your garden. You can make your yard less attractive to EFAs by reducing lawn watering and removing items that trap heat and moisture.

Discovered at VanDusen Botanical Garden in 2013, VanDusen staff have been working with the City of Vancouver, the Invasive Species Council of Metro Vancouver and Dr. Robert Higgins, Myrmecologist at Thompson Rivers University, to further their knowledge of this invasive ant species and explore control options.

While there are limited treatment options available for control of the European fire ant, particularly on a larger scale, successful control on a small scale may be achieved. A step by step guide for managing small populations of European Fire Ants developed by Dr. Rob Higgings of Thompson Rivers University can be found here.

 The City of Chilliwack will not be responding to reports of European Fire Ants on private property as this falls under the responsibility of the home owner. As per the BC Inter-Ministry Invasive Species Working Group website, please contact the Ministry of Agriculture and/or Dr. Higgins with Thompson Rivers University. Their contact information can be found here.

Ant samples can be sent to the Ministry of Agriculture's Plant Health Laboratory in Abbotsford for identification free of charge. Their website is http://www2.gov.bc.ca/gov/content/industry/agriculture-seafood/animals-and-crops/plant-health/plant-health-laboratory (although the website focuses on plant samples, they accept ant samples as well). The samples need to be submitted with the General Submission Form available for download on the Ministry's webpage.

Invasive Species Council of British Columbia: http://bcinvasives.ca/invasive-species/identify/invasive-species/invasive-insects-fungi/european-fire-ant

The slides from the presentation and a downloadable PDF information pamphlet are available at the bottom of this page.