Deer ticks feed on human and animal blood. As such, they can transmit dangerous bacteria and viruses to humans. According to Business Insider, ticks are most active in warmer seasons, and tick-borne illnesses are on the rise.

A case of the tick-borne Powassan virus was reported in Maine for the first time since 2017. Severe cases can be fatal. Two other cases of the virus were reported in northern New Jersey this summer.

Ticks can also transmit Lyme disease, babesiosis parasites, ehrlichiosis, anaplasmosis, and Rocky Mountain spotted fever. Lyme disease is the fastest-growing bug-borne illness in the nation.

Ehrlichiosis and anaplasmosis are flu-like illnesses, with symptoms like muscle aches, fever, chills, headache, and upset stomach. Both can be treated with antibiotics, but if left alone, can cause serious and potentially deadly symptoms.