I'm doing a phd in chemistry https://www.qnez.net/stmap_94gyirtx.html?tentex.cialis.xenical.starlix desconto lexapro lundbeck  Scientists know from watching snakes in the lab and in the wild that they have few problems tracking down bitten prey again. But they weren't sure exactly how the predators suddenly became master trackers. New research from biologists in Colorado reveals one trick that snakes have for locating and finishing their meals: A pair of proteins in their venom that "tag" the prey like a LoJack on a car, providing a chemical tracker that hungry snakes can follow.