The margay,
Leopardus wiedii or
Felis wiedii depending on which source you consult, is the most
agile cat on the planet.
Also known as the tigrillo or chulul, the margay is closely related to the ocelot but smaller, about the size of the average house cat. It is thought to be very rare, but its extreme furtiveness and exclusive habitation in dense forests make accurate population surveys impossible. The supposed rarity may stem from the margay's being nearly impossible to catch (there are only about 70 in zoos throughout the world), since populations are known to be distributed widely, from Mexico through Central and South America, all the way to Argentina.
It lives exclusively in tall trees and hunts whatever small birds and animals it can find there. Its double-jointed hind ankles rotate a full 180 degrees and allow the margay to hang and climb upside-down from a branch in the manner of a sloth. Margays have occasionally been seen jumping or dropping from this inverted position, only to catch hold of a lower branch. Like a squirrel, a margay can run straight up and down a tree trunk and leap between boughs. Its enormous eyes enable it to detect the slightest of movements in the black of night.
If you can somehow manage to adopt a margay, your household rodent worries will disappear. Naturalist G.F. Gaumer reported in 1917 of a margay kitten brought by local Indians and raised by him as a pet. Affectionate to its human housemate, the superb hunter scourged the mice and rats of Gaumer's tropical dwelling with a berserker's abandon.