Why Do Fleas Change Colour?

Fleas change colour to match their surroundings. One study in the United Kingdom found that sand fleas matched beaches that varied from black to yellow. The reason behind this amazing adaptation may be due to the genetic background of these fleas. In order to survive, sand fleas need to match the environment where they live.

While fleas change colour for a variety of reasons, the most common is that they change colour following a blood meal. This process is common among many other creatures and can be a defense mechanism for animals or to attract mates. The normal colour of adult cat and dog fleas is black to brownish black. Fleas will change colour after they feed as their blood swells up in size.

When fleas take blood, their colour will change to reddish-black. Their size will also double. However, newly emerged fleas will appear lighter. Also, the abdominal segments will not overlap anymore. Female fleas are bigger than males and have a heavier abdomen than males.

Another sign of a flea infestation is red spots in your cat’s bedding. This can indicate that they’ve been bitten by the fleas. Flea dirt is red when it’s warm and moist.