FORT COLLINS, Colorado (AP) — Tick season is starting across the U.S., and experts are warning the bloodsuckers may be as plentiful as ever.

Another mild winter and other favorable factors likely means the 2024 tick population will be equal to last year or larger, some researchers say.

“It’s very bad and has only been getting worse,” said Susanna Visser of the Centers for Disease Control and Prevention.

An increasing variety of ticks are pushing into new geographical areas, bringing unusual diseases. Exotic southern species like the Gulf Coast tick and the lone star tick are being detected in New York and other northern states, for example.

But the tick that experts warn of the most is a common blacklegged tick, which is found mainly in forests and spreads Lyme disease. Infection rates begin to peak in May, and U.S. health officials estimate nearly half a million Lyme disease infections happen annually.