[Melissa Block:] The next generation of bomb or drug-detecting technology could be the wasp. Scientists are training wasps to detect specific odors. They train the insects by exposing them to a target odor and then giving them sugar water so they associate the smell with their treat. The researchers have developed a device called the Wasp Hound. The wasps are put inside a plastic cylinder with a vent hole at one end, a fan that pulls air in and a tiny Web camera inside hooked up to a computer to monitor the wasps' reaction. If they detect what they've been trained to smell, they'll converge around the air hole `like pigs to a trough,'says one of the inventors, Joe Lewis, who's a research entomologist. He says the wasps have been trained to pick up a wide range of smells.
[Mr. Joe Lewis:] 24DNT, which is a breakdown product of TNT; cadaverine, which is a chemical that's associated with decaying flesh. For forensic purposes, we've shown that they show odors associated with marijuana. In other words, we have found that they have a very broad sense of detection capabilities; essentially it's unlimited.
[Melissa Block:] How long does it take to train these wasps to detect these new smells?
[Mr. Joe Lewis:] Well, very quickly. You can train them in as short a time as, say, five minutes, because the training protocol is to let them taste sugar water while they smell an odor. And you do that for 10 seconds and repeat it three times with a small break in between, and they've learned it.
[Melissa Block:] Have you ever found a wasp that just really couldn't learn?
[Mr. Joe Lewis:] They all learn. We have found that some are quick learners and respond more aggressively than others.
[Melissa Block:] I guess you're working against one fact of nature here, which is that wasps have a very short life span. You're not going to have these detectors with you for that long.
[Mr. Joe Lewis:] That is true. You know, there are advantages and disadvantages of this compared to, say, a dog. The advantage is that you can produce them by the thousands or more, and you can train them quickly and you can use them in a rather disposable manner. The disadvantage is that they don't live long, a couple of weeks. And we have to deal with shortcoming, but we can produce them very inexpensively and train them very quickly.
[Melissa Block:] Mm-hmm. And you can't rub their bellies.
[Mr. Joe Lewis:] Well, it would be a very tedious process. And you can't carry them around on a leash.
[Melissa Block:] Is there, do you think, some broader lesson here about insects, about the power of smell?
[Mr. Joe Lewis:] Oh, yes. There once was a staying `The deeper the well, the sweeter the honey.'Indeed, there was a time-and let me say, early in my profession that if I had talked about insects having this capability, I would have been laughed out of my profession.
[Melissa Block:] Is that right?
[Mr. Joe Lewis:] But as we move along and find what we're seeing, that learning in this highly sophisticated ability to integrate taste and smell and to quickly link and utilize these type things is a much primitive ability than we had imagined. In their world and on their territory, they are as sophisticated as we are. And they've been around a long, long time.
[Melissa Block:] I'll never look at them quite the same way.
[Mr. Joe Lewis:] Each day, I find that I look at them with much greater respect. In many ways, all these things are rather sacred.
[Melissa Block:] Joe Lewis, thanks very much.
[Mr. Joe Lewis:] Yeah. Well, thank you, Melissa.
[Melissa Block:] Joe Lewis is a research entomologist with the US Department of Agriculture in Tifton, Georgia.
[Robert Siegel:] This is NPR, National Public Radio.