Upon emerging from their cocoon, fleas will immediately seek a blood meal. They must do this within a week otherwise they risk dying of starvation.
When looking for food, there are a number of factors which can help a flea detect a suitable host but they are primarily attracted to visual and thermal stimuli. In other words, light and heat.
When placed in a dark area, studies have found that as many as 93% of fleas will move to a lighted area within 40 minutes. Green-yellow coloured lights have also been found to attract over twice as many fleas compared to standard light.
Interestingly, their attraction towards light is greatly enhanced when the light source is turned off quickly for a few seconds and then turned back on again. It’s thought that this interruption mimics a shadow cast by a potential host as it passes and the fleas will therefore jump in the direction of the perceived food source.
While you’re unlikely to sit around flicking the lights on and off, these findings can be very useful when it comes to flea control.
Other studies have found that flea traps which use intermittent light consistently, attract and capture significantly more fleas compared to those using a constant light source. In some cases, this method was found to be five to eight times more effective. In another experiment, intermittent light traps caught 82% of released fleas compared to standard light traps which caught a mere 10%.
Flea infestation activity has also been found to dramatically increase in response to heat. When a warm object is placed directly in their environment, they will jump wildly in random directions. The most obvious reason for this is because warmth signifies the body heat of a potential host.
Fleas naturally prefer to live in warmer climates as well. They are most comfortable in temperatures of about 65 degrees which is why pets make such great hosts. As well as being a plentiful food supply, they can also nestle in their fur to get the warmth they love.
Pets are a common way for fleas to enter your home but they’re not always the culprit. They can also be brought in via clothing and even second-hand furniture.
The most common signs of a flea infestation include:
- Your pet is scratching excessively, they have reddened skin or are losing fur. With dogs, their hind quarters are most commonly targeted and with cats, it’s their head and neck
- You may be able to see them. They’re approximately 2.5 mm long, their bodies are flat, they have six long legs, they don’t have wings and they can jump great distances
- Black specs around the house (normally easier to see on a light-coloured carpet or bed sheets)
- Put on a pair of long white cotton socks and walk around your house. Shuffle your feet to create warmth on the floor and linger in spots you suspect they’re inhabiting. If you do have a flea infestation, you will notice brown or black specs on your socks
- Flea dirt which resembles black pepper. If you’re unsure whether it’s flea dirt or normal dirt, rub the area with a moistened white towel. If it’s flea dirt, it will appear as tiny red streaks
- Flea eggs are tiny white ovals. They’re difficult to see so you may need a magnifying glass