The CDC says this is one of the worst tick seasons in recent years, with more than 229 out of every 100,000 ER visits involving tick bites — up from 167 patients last year — increasing the potential for victims to acquire Lyme disease.

Scientists have discovered that the bacteria behind Lyme disease and anaplasmosis have a sneaky way of surviving inside ticks—they hijack the tick’s own cell functions to steal cholesterol they need to grow.