Landing on Lunch

By Iain MacLeod on Friday, September 16, 2005.

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They're tiny, they cause pet owners to shriek in frustration... and they're fabulously fascinating insects. There are approximately 2000 species of fleas throughout the world. These hardy insects are marvelously well-adapted to their preferred habitat and host - your beloved pet.

Hi, this is Iain MacLeod from New Hampshire Audubon, bringing you Something Wild.

They are tiny, they cause pet owners to shriek in frustration... and they're fabulously fascinating insects. I'm talking about fleas.

There are approximately 2000 species of fleas throughout the world. But here in the United States the most common species is the cat flea. This is the flea you are likely to find happily living and dining on your cat or dog, or maybe even nibbling on your ankles.

These hardy insects are marvelously well-adapted to their preferred habitat and host - your beloved pet. Their bodies are very narrow, allowing them to move easily through dense hair and fur. As anyone who's tried to squash one knows, fleas can withstand enormous pressure. That's how they survive the scratching and biting of the host animal.

These animals do not have wings, but have long hind legs that can jump 150 times their body length. A human would have to leap the equivalent of a football field to match that- so fleas can easily launch themselves onto any unfortunate passing animals.

Like butterflies, fleas have a four-stage life cycle - egg, larvae, pupa, and adult. Female fleas lay up to 20 eggs per day, and 600 in a lifetime. The eggs hatch in several days, and the larvae take a week to several months to fully develop. Then they spin small cocoons, where, after a week, they become adult fleas.

But they may not emerge right away. Fleas must have a blood meal to survive and to mate, so they can remain dormant for up to a year until they sense that a host is close by.

The flea may be awakened by heat, noise or carbon dioxide, all of which mean a tasty meal may be nearby. The famished flea will then literally leap into action, in the hopes of landing on lunch.

Something Wild is a joint production of New Hampshire Audubon, New Hampshire Public Radio and Society for the Protection of New Hampshire Forests. For Something Wild, I'm Iain MacLeod.