What Attracts Fleas

What Attracts Fleas? Trapping & Killing

Fleas are a health hazard and a nuisance to both humans and pets; they may cause allergy dermatitis, skin infection, welts, and shedding or transmit murine typhus and bubonic plague.

So, in this article, I will be tackling the question “what attracts fleas?” Well, fleas are attracted to both thermal (heat) and visual (light) stimuli. Additional cues include air movement and carbon dioxide that denote the presence of a likely host. 

  • Depending on the fleas’ life stage, these organisms may be attracted by exhaled ghost-breath, movement, darkness, food, and warmth. 

Details:  What Attracts Fleas? Trapping & Killing

Once the fleas emerge from the pupa cocoon, they will require a quick blood meal (within a week) to avoid starvation.

  • Therefore, the queues outlined below are the ones that will help attract the fleas to a good host such as cats and dogs or even humans.

Notable attractant cues for fleas to their hosts are thermal or visual. But when the fleas detect multiple stimuli or cues, they will be attracted better and jump faster.

1. Heat (Thermotaxis) or Flea Host Warmth

a. Increases Activity

Fleas, especially cat fleas, are known to be positively thermotactic i.e. their activity will increase when there is an increase in heat around.

  • For example, the fleas will jump all over when they detect a warm object such as a room heater in their surrounding.

b. Attraction to Suitable Hosts

Since animals emit body heat, the fleas will get attracted to such warmth as the host gets near.

The notable temperature that will attract the freeze will be around 40 degrees centigrade (104 degrees F).

  • But the fleas may also get attracted to temperatures around 50 degrees centigrade (122 degrees F).

This point alone makes sure that fleas are unable to differentiate between the homes of various animals including their hosts.

Therefore, it might be incorrect to say that fleas Will only be attracted to specific temperatures that are known to be those of their good hosts.

However, using heat or warmth alone as a stimulus to attract fleas might not work.

This is because the fleas are intelligent and they’ll get near the source of warmth and jump back and forth to determine how deep are intensive it is.

  • The inclusion of additional stimuli like air movement can help to attract the fleas more.
  • Therefore, that thermal-based flea trap might not be effective if that is the only stimuli it relies on.

Further, using a light-based flea trap or even including heat as an additional stimulus may not give you better results in attracting fleas.

In summary, I might note that the more stimuli or cues are very many more responsibility in helping fleas find a host.

c. Abandoning a Cold Host

Still on the body temperature of the hosts, please will jump off such a host when it gets cold or if it’s dying.

  • During such circumstances, the bugs will prefer to jump to another warm host (animal or human) in the environment.
  • Instances in which this can happen is when you are pet such as the cat or dog kills a smaller animal such as a rat.

So, when the rat dies and gets cold, the fleas will detect the temperature change and thus jump on to the nearest warm animal like your cat or dog.

d. Fleas Larve Emerge from Cocoon

Flea larvae will emerge from their closed cocoons due to the presence of a number of triggers which include heat plus pressure.

  • Pressure and heat will notify the fleas that there could be an animal in their surrounding which may be a suitable host.

However, even human breath that is warm may make the flea larvae emerge.

Notably, in the absence of pressure and heat, the larvae of the fleas sit dormant for even 5 months.

2. Light (Phototaxis) Will Attract Fleas

Adult fleas are highly sensitive to light. A recent study shows that over 90% of fleas will jump into a lighted place in under 1 hour.

Further, adult fleas will jump onto high objects especially those in a lighted location waiting for a suitable host.

a. Differences in the color of light

Colors can be classified in different wavelengths and fleas are able to detect the different wavelengths that are under 600 nanometers but over 300 nanometers.

Experts note that light that is green-yellow (whose wavelength is around 500 to 530 NM) will attract the fleas best.

Compared to standard light, this light that is green-yellow will attract double the number of fleas.

Therefore, innovators have manufactured flea traps that use a filter that is green-yellow to improve the device’s performance.

Notably, there are filter colors that will not attract fleas as good as standard light and these include medium blue, yellow, magenta, and red.

b. The attraction of fleas to intermittent light

You will greatly improve the fleas’ attraction if you briefly and quickly interrupt the light source ( off for 5 seconds and on for 10 minutes).

  • But why does intermittent seem to produce good results in attractive fleas?
  • When the interaction of the light source mimics some shadow of a suitable host that may be passing nearby.

Therefore, on sensing the perceived shadow, the fleas will jump in its direction.

Experts have designed flea traps that utilize intermittent lighting (as opposed to just constant light) and these new devices have trapped more fleas.

3. Movement – Especially of animals

Please will mainly be attracted to animals especially when they are moving or if they’re showing other notable stimuli.

For example;

  • A recent study showed that only 17% of fleas or attracted to some stationary object well over 80% what attracted to the same object while it was set in motion.

a. Movement of Air (Air Currents)

When air currents are considered a notable stimulus for the attraction of fleas, this alone is not enough.

For example;

  • cat fleas won’t get attracted to air currents coming from a fan in your house.

However, if these air currents are sensed together with another stimulus such as carbon dioxide, the fleas will get attracted better.

But when the air currents come in short bursts, they may make the fleas flee.


There are other factors that may affect how fleas get attracted; these include host size, host color, flea gender, flea age, time of day, carbon dioxide, physical contact, warmth, gravity, host odor, air currents, and light movement.