In areas with abundant oaks and mice, it appears tick numbers will be very high based on data collected at the Cary Institute of Ecosystem Studies. The current mild winter weather does not cause a rise in tick populations, however, it can change tick behavior. Adult ticks, which are slightly larger than a sesame seed, are normally dormant in winter. Ticks start to seek a host for a blood meal whenever temperatures rise well above freezing. The warm winter of 2011-12 induced earlier than normal tick activity.
People should be especially aware when outdoors during the May-July season for nymphal black-legged ticks. Nymphal ticks are often responsible for spreading Lyme disease to people. The disease can be debilitating to humans if undiagnosed, causing chronic fatigue, joint pain and neurological problems. Lyme disease is the most common tick-borne illness in the United States.