Insect Bites & Stings in Canada: What to Know & What to Expect

Most insect bites and stings cause a small, itchy bump and may develop a surrounding raised area filled with fluid (called a wheal). In most cases, symptoms improve within several hours and can be safely managed at home. Reactions vary depending on the insect and the individual’s sensitivity.

Fleas

Flea bites may appear in small clusters or lines. Sensitive individuals may develop papular urticaria, where multiple itchy red bumps form.

Pet fleas commonly bite below the knees, especially around the ankles. Bites can also appear on the forearms if pets are held or carried.

Mosquitoes, Midges & Gnats

These insects often leave small itchy bumps (papules). People sensitive to bites may develop wheals or fluid-filled blisters. In many countries, mosquitoes can transmit diseases such as malaria, but in Canada seasonal concerns are more commonly focused on nuisance bites and West Nile virus surveillance.

Horseflies

Horsefly bites can be painful and may produce a large wheal. Some individuals experience dizziness, itching, weakness, or swelling. Because horseflies slice the skin to feed, bites may take longer to heal and can be more vulnerable to infection.

Bedbugs

Bedbug bites are usually painless at first. People bitten for the first time may not react, while others may develop itchy lumps or wheals. Bites are commonly found on exposed skin such as the arms, hands, neck, and face.

Ticks

Tick bites are often painless and may leave a small red bump. Some people experience swelling or bruising. Ticks can carry infections, including Lyme disease, which is present in parts of Canada. Early detection and removal reduce risk — contact a healthcare provider if symptoms develop after a tick bite.

Mites

Mite bites can cause small itchy bumps or blisters. When mites are associated with pets, bites may appear on the thighs or abdomen; otherwise, they may affect exposed skin.

Spiders

Spider bites typically leave a small puncture mark and may cause redness, soreness, or swelling. Severe reactions are uncommon, but symptoms such as nausea, dizziness, or sweating warrant medical attention.

Bees

Bee stings usually leave a stinger with a venom sac in the skin. It should be scraped off using the edge of a card rather than pinched or pulled, which can squeeze additional venom into the skin.

Wasps & Hornets

Stings are often sharp and immediately painful. A red, swollen, itchy area may develop afterward. Unlike bees, wasps and hornets do not leave behind a stinger and can sting more than once.

First Aid & Allergy Awareness

Most bites and stings are mild, but some people may experience stronger reactions. First aid awareness helps Canadians recognize when symptoms are routine and when medical care is appropriate — particularly for swelling affecting the face, breathing, or swallowing.

Outdoor workers, hikers, families, and summer camps often benefit from St. Mark James Training in first aid and CPR/AED, which supports safe responses to outdoor allergic reactions and other environmental injuries.

Educational Disclaimer

This content is for public education in a Canadian context and not a diagnostic tool. Seek medical care for concerning symptoms, suspected tick-borne illness, or severe allergic reactions.