Difference between Fleas and Ticks

Fleas and ticks can be alarming and can even be a danger to the family, but which is which? Are ticks more dangerous than fleas or is it vice versa? How can we distinguish a flea from a tick?



Fleas vs Ticks
Cat flea under an optical microscope

Fleas are wingless insects with mouthparts that are capable of piercing skin and sucking blood. They are an external parasite that lives by feeding on the blood of mammals and even birds. They measure 1/16 to 1/8 of an inch (1.5 to 3.3 millimeters) long. These parasites are agile and can jump vertically up to 7 inches (18 centimeters) and horizontally for up to 13 inches (33 centimeters), thanks to their long and powerful legs. In ideal conditions, a flea can live as long as one and one-half years (but usualy about 100 days).

Flea’s life cycle:

  • Egg: laid by a female in batches and can reach a number of 20 or so, taking two days to two weeks to hatch (can lay up to 5000 or more eggs during their lifespan)
  • Larvae: emerge from eggs and feed on available organic materials including dead insects, feces, and even vegetable matter
  • Pupae: when provided with an adequate supply of food, larvae becomes pupae within 1 to 2 weeks and will be ready to emerge in another week or two. (Will be looking for a host through vibrations, sound, heat, and carbon dioxide)
  • Adult Flea: reaches adulthood when primary goal is feeding and reproducing

Fleas are not only a nuisance to their hosts by causing an itching sensation, but can also cause diseases by acting as a vector (carrying and transmitting infectious pathogen into another living organism). For humans, fleas usually settle in a person’s hair for less than ten minutes and will cause soreness and itching. With pets on the other hand, fleas settle under the coat/fur.


A fully blood-fed tick with an unfed tick

Ticks are considered small arachnids that can measure from ¼ to 1/8 of an inch long. Like fleas, they live by hematophagy on the blood of mammals, birds, amphibians and sometimes even reptiles. They usually flourish more in places with warm and humid climates due to the certain amount of moisture they need to undergo metamorphosis. They are commonly seen on domestic animals and can cause considerable harm. They undergo a life cycle that requires three blood meals, once at the larva stage, once at the nymph stage, and lastly at the adult stage.

Tick’s life cycle:

  • Egg: laid by a female tick (can lay up to 5000 eggs depending on the size and amount of blood it ingests)
  • Larvae: hatches 2 to 5 weeks afterwards and will look for a blood host for 3 to 7 days. Later will molt.
  • Nymphs: After 2 weeks, a larva will develop into a nymph and then feed for 5 to 10 days and then develop into an adult.
  • Adult: feeds on a host for about 2 months. Female ticks will then lay its eggs again.

As in the case of a flea, tick bites can cause different diseases including Rocky Mountain spotted fever (also known as blue disease, a lethal illness that can cause fever, nausea, emesis, severe headache, muscle pain, and lack of appetite) and Lyme disease (affects multiple body systems and can cause headache, muscle soreness, fever, and much more).

Fleas vs Ticks

What’s the difference between fleas and ticks? Both live by hematophagy, causing harm to their hosts, and laying thousands of eggs, but they actually have their differences.

Fleas are insects, while ticks are arachnids, but that’s just the start. Fleas need fewer hosts than ticks, they don’t require the three hosts cycle that ticks need. The lifespan of a flea can go up to 100 days, while a tick can go for up to 3 years. Also, fleas lay their eggs on hosts, unlike ticks that fall off the host and lay eggs someplace else. For their ability to survive, ticks are known to be tougher. Both being a parasite and a vector, fleas can transmit bartonellosis and tapeworm while ticks can transmit potentially deadly diseases including Lyme disease and Rocky Mountain spotted fever.

Comparison Chart

Fleas Ticks
Insect Arachnid
Seeks a single host Seeks different hosts
Agile Not agile
Smaller Small
Lives up to 100 days Lives up to 3 years
Lays eggs on hosts Lays eggs wherever
Over 2,000 species Over 800 species
Can cause diseases Can cause deadly diseases


Here is a video that can explain further the differences of fleas and ticks.