A battery-powered ladybug, for example, says it "helps protect your baby from West Nile virus" by mimicking "the sound of a dragonfly's wing beat. The mosquito's mortal enemy."
And it can be clipped to strollers; a plus for parents.
The $12 bug is a big hit at a Buy By Baby store in New York City.
"Every year we sell hundreds in each of our stores. So you do the math. We probably sell thousands every year and so far so good," says store manager Barry McHale.
While these products are flying off store shelves, scientists caution, "Buyer Beware": not only will these devices leave you unprotected, they'll also take a bite out of your wallet.
"Most of the products are laughable because, in the first place, they're not based on science," says Dr. Wayne Crans, director of mosquito research at Rutgers University.
"Mosquitoes do not flee an area when they hear a dragonfly approaching," he says.
CBS News asked Crans to put the ladybug to the test.
The results came in seconds.
"If anything, they're biting more with the ladybug than without," Crans says.
"They do not work at all," he concludes.
In a statement, the ladybug's maker, Prince Lionheart, said, "We are confident we have an effective mosquito deterrent."
But that effectiveness depends on "climatic conditions, the individual human chemistry involved and the level of intent of the mosquito."
Earlier this year, the Federal Trade Commission forced a company called Lentek to stop making false claims about its "dragonfly" technology.
"What the FTC knows from having looked at ultrasonic and sonic pest control devices is that they don't work," says FTC associate director Elaine Kolish.
The FTC says the Lentek case should serve as a lesson.
"These other marketers, if they're savvy, are going to take note of the commission's actions or they too may face similar action," says Kolish.
Crans has a theory as to why people keep buying these products: "There's a sucker born every minute."
Perhaps more West Nile suckers than bloodsuckers.