"Ixodes" ticks have three life stages that require a host: larva, nymph and adult. Each stage requires a blood meal to progress to the next life stage. The nymph stage frequently bites humans and is the stage in which "I. scapularis" is most likely to infect a human host with a pathogen. The most common reservoir (or host) for "I. scapularis" are white-footed mouse and white-tail deer. The most common reservoirs for "I." "cookei" are skunks, woodchucks and squirrels. Humans are incidental hosts which means the ticks do not need to feed on humans to survive, humans are merely the host they find at the time for their next blood meal.