Tim Lockley: Geckos fit right into the season

I've got an idea for All Hallows' Eve. Collect a gaggle of geckos and scatter them around your front door. When Trick-or-treaters show up, the little critters (the geckos, not the children) will be startled enough to attempt to leap to safety, landing on the unsuspecting costumed candy collectors. If you've ever had a gecko nestle itself against the back of your neck, you can see how well they might fit into the holiday.

Geckos are about a fifth of all species of lizards. They can be found on every continent, with the exception of the Antarctic. As would seem appropriate for a poikilothermic (cold-blooded) creature, the majority are found in warmer climes. You can divide geckos into two major groups: those that blink and those that don't. The blink-less ones can be further divided into two subgroupings: those with sticky feet and those without stickiness.

There are two factors that further separate them from other lizards. Their metabolism is one. It's unusual in that it allows them to be active at night, a time when any self-respecting lizard would be sluggish and tucked away sleeping the night away.

A second feature is the structure of their throat, which allows them to have a voice. When I was in Vietnam, the geckos in our hooch would crawl up the screens and yell at us late at night. After a few restless nights of being serenaded by these diminutive allies of the Viet Cong, I volunteered to work the grave shift.

Geckos are predators. For the most part, they eat insects, but they also will eat spiders and small snails. One of their favorite snacks is young cockroaches.

In turn, geckos supply larger predators with their meals. Birds, cats and snakes are the main consumers of geckos. If caught by the tail by a peckish predator, geckos can detach their tail. It will twitch for a while, distracting the predator while the majority of the gecko makes good its escape. The tail eventually will regrow. If the tail is only partially detached, a second tail will grow along side the original. Every once in a while, a gecko is found with up to three tails.

If, for some reason, you don't want these useful and fascinating creatures hanging around your house, here's something you can do to ameliorate the problem. Turn off your porch light. Insects are attracted to light and geckos are attracted to high concentration of insects. If you have to have some form of light, change the bulb to one of those old-fashioned yellow "bug" lights or one of the newer sodium vapor lights. Since insects aren't attracted to these particular wavelengths of light, the geckos will move off in search of happier hunting grounds. It might take a while for the geckos to get the message. It's going to take some time before they realize that their meal ticket is gone, but eventually they'll leave.

Personally, I like the little guys and hope to have a few at my front door come Halloween. I can hear the squeals now.

Tim Lockley, a specialist in entomology, is retired from a 30-year career as a research scientist for the U.S. Department of Agriculture. For answers to individual questions, please send a stamped, self-addressed envelope to Tim Lockley, c/o Sun Herald, P.O. Box 4567, Biloxi, MS 39535.