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Life cycle of deer ticks A tick needs a blood meal to progress through each stage of its two-year life.
First yearMay-June
Adult females lay eggs and die.
July-Oct.
Larvae hatch and seek a blood meal, typically on a small rodent or bird. Larvae are born disease free and acquire pathogens from an infected host.
Oct.-April
Larvae molt into nymphs, stay dormant over winter.
![]() Females typically lay 2,000-3,000 eggs in leaf litter.
FIRST BLOOD MEAL
![]() White-footed mice often carry the Lyme bacteria.
Second yearMay-Sept.
Nymphs become active and try to grab hold of a passing person or animal. Ticks can detect hosts through odors, body heat, moisture, vibrations, and visual cues.When infected nymphs feed, bacteria can migrate from tick to host; in most cases the tick must be attached for at least 36 hours to transmit pathogens. After feeding, nymphs drop off and molt into adults.
Sept.-Dec.
Females seek to feed once more before mating.
Jan.-Feb.
Adults remain active all winter on warm days.
Mar.-April
Adults that did not feed in the fall continue to seek a host.
SECOND BLOOD MEAL
![]() Infected nymphs pass pathogens to humans.
THIRD BLOOD MEAL
![]() A deer can carry a tick for miles.
SOURCES: TickEncounter.org; US Centers for Disease Control and Prevention Active monthsThe actual number of ticks present can vary from place to place and year to year.Chart shows when each stage is most prevalent wherever deer ticks are found.
Adults:Possibly infected but large enough to be seen
Nymphs:Tiny and infected
Larvae:Possibly infected
Adults:Possibly infected but large enough to be seen
![]() JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
JAN
Most likely time to catch Lyme disease
Relative sizes
![]() Larvae
Nymph
Adult male
Adult female
Engorged female
Enlarged![]() Larvae
Nymph
Adult male
Adult female
FeedingTicks can attach to any part of the human body but are often found in hard-to-see areas such as the groin, armpits, and scalp.
1.
The tick inserts its barbed feeding tube (right) through the outer layer of skin.
2.
The tick secretes a cement-like substance to stay firmly attached.
![]() Detail of mouth parts
3.
Tick saliva contains an anesthetic property that keeps the host from feeling the bite.
4.
Pathogen can be exchanged when tick saliva and blood from the host mingle at the bite site.
5.
After feeding for several days, the tick drops off and molts into its next stage of life.
SOURCES: Kirby Stafford III, Connecticut Agricultural Experiment Station; US Centers for Disease Control and Prevention Blood pool
![]() Tick embedded in skin
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