Blacklegged ticks are most often found in forests as well as overgrown areas between woods and open spaces. The risk of a tick bite starts when the weather warms up in the spring and ticks become active. This continues during the summer months through until the fall when the temperature goes below freezing.
Ticks are usually picked up when brushing against vegetation like grasses and shrubs. Once on bare skin, they attach by their mouth parts. Ticks can attach to any part of the human body. In most cases, the tick must be attached for 24 to 36 hours before the Lyme disease bacterium can be transmitted.
The risk of Lyme disease varies with the stage of the tick (larval, nymph and adult). Larval ticks (youngest stage) may bite but they are not infected with Lyme disease. Most people are infected through the bites of immature ticks called nymphs (the juvenile stage of ticks that have developed from larval ticks). Nymphs are tiny (less than 2 mm) and difficult to see. They usually feed during the spring and summer months. Adults develop from nymphs and are larger and are more likely to be found and removed before they have had time to transmit the bacteria. Adult ticks are most active during the cooler months of the year.