The Pittsburgh Zoo's two zebras have been vaccinated against West Nile Virus — the one vaccine approved for fighting the virus works only on equine species, including horses and zebras.

But according to zoo spokesperson Connie George, other steps are being taken to protect all of the zoos inhabitants — by fighting mosquitoes.

"Mosquitoes lay their larvae on still water, and the larvae need still water in order to breathe, so if the water has a current, it won't hatch... so it will just get washed away."

Armed with this knowledge, George says, it becomes easy to prevent West Nile outbreaks without any vaccine.

"So all the water that we have in the zoo we're monitoring and making sure that it has a current, if not we're changing it daily... We're spraying some of our animals with insect repellant."

George says birds are the animals most susceptible to West Nile Virus, and one of the zoo's elderly owls recently died after contracting the virus — but the rest of the zoo's birds have been tested, and are healthy.

More information's available on the web at GreenWorks.tv. I'm Brad Linder.