Difference Between Fleas and Lice (With Table)

There are different types of parasites. A parasite simply means those animals or insects which live inside another organism (host) and gets their food from them. These are classified as protozoa, helminths, and ectoparasites. Ectoparasites are the type of parasites that lives on the outer surface of the host. The very common example of this class could be lice and fleas. Both of them are the type of Ectoparasite which lives on the external surface of human, animal, and birds respectively.

Fleas vs Lice

The main difference between fleas and lice is their host and their habitat. Lice are found mainly on the human on their hairy parts, mostly hairs or the underarms, whereas Fleas are found mainly on the skin of birds and animals in their warm parts of the body. Another difference could be the ability of fleas to jump and the pain they cause. Lice cause less pain in comparison to fleas which cause slightly more pain.

Fleas are the type of ectoparasites which are commonly founded in the animals and birds, and it does not have wings and can cause various diseases such as plague and myxomatosis, etc. with its bite which also causes more pain. It is not found in humans. It can bite them (feet or legs) but not live on them.

Lice are also a type of Ectoparasites found on hairy parts of the human body. It can also be found on mammals and birds but mainly lives of humans. It is spread by direct contact or in an unhygienic environment. It does not cause much pain but irritation and itching. The presence of these can be felt on the skin.

Comparison Table Between Fleas and Lice

Parameters of Comparison




Rat fleas, human fleas, cat fleas, and sand fleas

Head lice, body lice, and pubic lice


live in warm parts of the body

mainly live on hairy parts of the body


belong to the order Siphonaptera

belong to the order Phthiraptera


fleas can grow up to 1-4 mm

the lice can grow up to 4.5 mm

Mode of Nutrition

blood parasites

symbiotic scavengers

What is Fleas?

It is a type of parasite feeding of blood or mammals and birds. This could be rarely found in humans.


  1. Wingless.
  2. Light brown or reddish in color.
  3. Small and disproportional head.
  4. Large hind six legs

The main types of Fleas are:

  1. Cat fleas: found in cats, also known as Ctenocephalides felis.
  2. Dog Fleas: found in dogs, also known as Ctenocephalides canis.
  3. Human Fleas: found in the human body, mainly feet or legs, also known as Pulex irritans.


  1. Intense itching.
  2. Swollen or red body part.
  3. A lump is seen on the infected area of the body.
  4. Minor infections

Fleas sometimes can lead to serious infections, such as rat fleas can cause bubonic plague and flea-borne typhus, and cat fleas can be responsible for the transmission of tapeworms. The one thing that mainly differentiates of from other ectoparasites is its ability to move fast and jump long.


For treatment of the fleas, first of all, you have to make sure what is the source or carrier of these fleas. Suppose the pet has fleas which can be detected by noticing if they are scratching and itching on a particular area more frequently or if there is any red spot or swelling. And after detecting it, they should be cleaned with anti-flea shampoo. And in some serious cases, a doctor should be considered.

What is Lice?

Lice are small parasites that suck blood from humans, mammals, and birds. Three types of lice generally found among human beings are: 

  1. Head Lice: also called Pediculus Humanus Capitis. These types are found in the head and can be seen roaming around the neck or the ear. 
  2. Body Lice: also called Pediculus Humanus. These types are found in the body or clothes of a person, mainly dues to unhygienic.
  3. Pubic Lice: also called Pthirus pubis or crab. These are found in the pubic area, such as eyebrows or the chest hair.


  1. If there is itching in some area.
  2. If there is the sensation of tickling in the body.
  3. If lice eggs or lice are visible in cloth or body.
  4. If bite marks are found on the body parts.


  1. Direct physical contact from the head.
  2. Unhygienic clothes or if clothes are stored tightly in a particular area for a longer duration.
  3. Transmitted from friends or family.
  4. If an infected bed or furniture is used.


  1. Proper cleaning of clothes and hygiene should be maintained.
  2. Any direct head-to-head contact should be avoided, especially with the stranger.
  3. Proper distance should be maintained from the infected person.

Main Differences Between Fleas and Lice

  1. The shape of their body is also different from each other, lice are oval, and fleas are flat. 
  2. Other than the size and shape, they also differ in the color of their body. Lice are dark grey, and fleas are reddish.
  3. The colors of the eggs lay by them are also different in colors. Fleas lay eggs of white color, and lice lay eggs of coffee color.
  4. The mode of nutrition for lice is symbiotic scavengers, and the mode of nutrition for all fleas is blood.
  5. Fleas can move quickly, but this ability lacks in the lice.
  6. Fleas also can jump because of their long hind legs, but lice cannot jump from one place to another.
  7. There are three life stages of the lice, but there are four life stages of the fleas.
  8. The lice have more host specificity than the fleas.


Both lice and fleas have several similarities such as both are ectoparasites, both of them does not have wings and have six legs with piercing mouth, both of them bite their respective hosts and such their blood, causing itching and swelling it the bitten part (area) both of them are vectors of disease, both of them lay eggs which are oval in shapes.

But despite all the above similarities, they are very different from each other, i.e., clear from all the above differences. Moreover, they can be removed from their hosts by different methods, and to avoid this, organisms should not be in any physical contact with anyone who has them on their body or animal, and proper hygiene should be maintained.


  1. https://pediatrics.aappublications.org/content/110/3/638.short
  2. https://www.sciencedirect.com/science/article/pii/B9780128140437000108