Flea & Tick Life Stages
Fleas and ticks are two separate parasites with very different life cycles. Both can transmit disease. Philadelphia's deer tick population carries Lyme disease — knowing the nymph stage is critical since it's the primary transmission stage.
Cat Flea Egg
0.5mm, white, oval, laid in pet fur but fall off into carpet, furniture, and flooring within seconds. One female lays 20-50 eggs per day. Eggs are slippery and nearly invisible on light surfaces.
Flea Larva
Tiny white worm, 1-5mm. Feeds on adult flea feces (digested blood) in carpet fibers. Photophobic — moves away from light into deep carpet pile. This stage lasts 5-18 days.
Flea Pupa (Cocoon)
Silk cocoon with sticky outer layer that collects debris as camouflage. Can remain dormant for 5 months awaiting vibration, body heat, and CO2 signals. This is why vacated homes seem to explode with fleas.
Adult Cat Flea
1-3mm, dark reddish-brown, laterally flattened. Jumps 7 inches vertically. Bites within seconds of finding a host. Can transmit tapeworms and murine typhus. Begins laying eggs within 48 hours of first blood meal.
Deer Tick Nymph
Poppy-seed sized (1mm), tan/brown. Responsible for 80-90% of Lyme disease transmission — too small to notice before the 36-48hr attachment needed for transmission. Peak activity: May-July in Philadelphia.
Adult Deer Tick
3mm (unfed) to 10mm (engorged). Female is orange-brown with dark shield; male is all dark. Active October-April in Pennsylvania. Check for ticks after any outdoor activity — wooded areas, leaf litter, tall grass.
Images: Wikimedia Commons — free educational use