Fleas are small flat insects 1.5mm to 3.3mm long. They can jump incredible distances compared to their size.

The body of a flea is very tough and can withstand squeezing between fingers. It is often necessary to crush between fingernails to kill them.

In Britain the most common fleas are cat or dog fleas. Human fleas are rarely identified, however the treatment of this pest is the same regardless of subspecies.

Adult fleas feed on the blood of their host and indeed need this blood to become reproductive. The eggs and larvae fall from the host onto bedding and carpets where they remain until they mature to adulthood.

Survive for long periods

As a pupa the flea will remain virtually dormant for many months if conditions are not suitable, or if there is no host animal to feed upon. Once an adult has fed it can survive for long periods without food (up to a year is not uncommon). 

When food is available fleas will feed every few days. 


Often an infestation goes unnoticed as the fleas are feeding on the family pet rather than humans. The infestation becomes apparent when either the flea burden becomes so great that members of the household are bitten or circumstances change. For example:

  • Returning from holiday where a pet has spent time away from the home.
  • Moving home.
  • The pet dies

In each case the fleas will have become hungry and will then feed on humans or other warm-blooded creatures that enter the property.

Flea bites

Flea bites are small red bumps, often in clusters or lines and may remain itchy for several weeks.


The whole property will need to be treated in order to control the infestation and any pets must also be treated with flea spray at the same time.