That has officials concerned. That's because blacklegged ticks (also known as deer ticks) transmit Lyme disease, which is increasing in Pennsylvania. - Advertisement - Most people contract Lyme disease from bites from nymphs, officials said. That's because their active season is when so many people are outdoors and they are so tiny they can be easily overlooked. The bite isn't felt. Last year, DEP's tick surveillance program found 1,200 nymphs across the state. "We're on a path to double that," DEP Secretary Patrick O'Donnell said at a recent news conference. Ticks are collected using white felt drags that sample low-lying ground cover and understory vegetation for questing ticks.