The lifespan of the giant tortoise is about 150 years, making it the longest-living animal on the planet. In captivity, some giant tortoises have lived as long as 177 years.

Bats are the only mammals capable of true flight. A bat's wing is constructed very much like the human hand, with extremely elongated fingers and membranes stretched between. Bats can be found almost anywhere in the world except for areas with extreme temperatures such as polar regions and deserts. In fact, there are almost 1,000 species of bats worldwide, ranging in size from less than an inch to almost six feet. Many species of bats are considered endangered.

Able to dive at almost 200 miles per hour, the peregrine falcon is not only the fastest flying bird in the world, but the fastest animal on earth. Although several subspecies including the Arctic peregrine falcon and the American peregrine falcon were once considered endangered, they have made a successful recovery and are no longer listed on the endagered species list. The peregrine falcon can be found on every continent except Antarctica.

A newborn kangaroo is about 1 inch in length -- approximately the size of a lima bean. Still essentially a fetus, the newborn kangaroo "swims" through its mother's fur to reach her pouch where it latches onto a teat which swells inside its mouth. The baby kangaroo or joey will remain fused to the teat for four to five weeks. After 7 to 8 months inside its mother's pouch, the infant will venture outside, returning only to feed. In the case of multiple infants belonging to the same mother, each infant feeds only from its own individual teat, and each teat provides a different mix of nutrients depending on the age of that particular infant.

The gestation period of a blue whale is approximately 10 to 12 months. Usually, only one calf is born at a time, although twins have been reported on rare occasions. Most calves, which weigh about 2 1/2 tons, are born in late fall or winter and will usually stay with their mother for 6 to 8 months until they are weaned.

The smallest mammal in the world is the bumblebee bat which lives along the River Kwai in western Thailand. An endangered species, the bumblebee bat is not much larger than an actual bumblebee (1.2 in) and weighs less than a penny (0.07 oz). Of course, there are several mammals similar in size to the bumblebee bat, and the designation of which one is actually the smallest can sometimes be contentious. Another animal which is sometimes awarded the title of "world's smallest mammal" is Savi's pygmy shrew, a tiny insectivore small enough to run through the tunnels of large earthworms. Each day, this pygmy shrew consumes insects and spiders up to 2 to 4 times its own body weight.

A wolf has two hundred million scent cells inside its nose and can smell 100 times better then a human being. Under favorable conditions, it can smell its prey from about 1.75 miles away.

According to the Guiness Book of World Records the most poisonous (or venomous) spider in the world is the Brazilian wandering spider (Phoneutria nigriventer) or banana spider. Its venom is so potent that just 0.006 mg (0.00000021 oz) can kill a mouse, making it the most active neurotoxic venom of any known spider.

A hummingbird can flap its wings about 80 times per second, causing an audible humming sound. Due to the unique structure of their wings, hummingbirds can fly left, right, up, down, backwards, or even upside down. They can also hover by flapping their wings in a figure-eight pattern. And their wings aren't the only fast-moving body part -- they have a heart rate of approximately 1,260 beats per minute!

Because of its extremely long neck, the giraffe must rely on its oversized heart (two feet long and twenty-five pounds!) to pump blood all the way to its head. As a result, the giraffe has the highest blood pressure of any animal: 280/180 mmHg (millimeters of mercury) at heart level when prone -- more than twice the blood pressure of an average human. Not surprisingly, because of their high blood pressure, giraffes are prone to heart attacks.