The largest spider in the world is a tarantula called the Goliath Birdeater. An adult can weigh over four ounces (about the size of a large mouse) and has a leg span of up to 12 inches. The spider was given its unique name by Victorian explorers who witnessed one eating a hummingbird although birds are not typically part of its diet. They survive mostly on small insects and meal worms but will occasionally eat small rodents such as mice, shrews and moles.

Wild goliath birdeaters are a deep burrowing species, found commonly in marshy or swampy areas. Goliath birdeaters usually live in burrows in the ground that they have either dug themselves or have been previously abandoned by rodents or other similar creatures.

The goliath birdeater is fairly harmless to humans, as are most species of tarantulas. Like all tarantulas, it has fangs large enough to break the skin of a human and they do carry venom in their fangs and have been known to bite humans when threatened, but the venom is relatively harmless and its effects are comparable to those of a wasp’s sting. Tarantulas generally bite humans only in self-defense, and these bites do not always result in envenomation. The goliath birdeater has poor eyesight and mainly relies on vibrations in the ground that they can sense from their burrows.

Source: Wikipedia. Posted by the science guy for best selling science toys at Atomic Elephant Toy.

Mimosa pudica (also known as the “sensitive plant” or “Tickle Me plant”) is well known for its rapid leaf movement. In the evening the leaflets will fold together and the whole leaf droops downward. It then re-opens at sunrise. This type of movement is called nyctinastic movement. The leaves also close up under various other stimuli, such as touching, warming, or shaking (hence the name, Tickle Me plant).

The stimulus can also be transmitted to neighboring leaves. The scientific term for these are seismonastic movements. The movement is caused by “a rapid loss of pressure in strategically situated cells that cause the leaves to droop right before one’s eyes”. [Wikipedia] This characteristic is quite common within the Mimosaceae family. Gradual loss of pressure can also cause the plant to close its fronds as is sometimes the case when it is exposed to a strong wind, rain or sunlight.

Why the plant’s leaves close up when exposed to these external stimuli is most likely an evolutionary response. As the leaves fold down, sharp thorns are exposed and would make the plant less tasty for herbivore animals that might want to eat them.

Posted by the science guy for the best selling science toys of 2008.

This is a very generic question, but one that actually gets asked quite frequently.  Of course, the short answer is that snakes have a varied diet, depending on factors such as their species, size, age, geographic locale, etc. A fairly accurate answer for what most snakes eat might be: insects, worms, lizards, birds, small amphibians such as frogs and salamanders, and small mammals such as rats, mice and voles. But even this answer could vary depending on a location. A common garter snake that lives in a wooded area near a pond will likely eat more frogs than the garter snake found in your backyard which might live entirely on insects and the occasional mouse.

The more interesting answer is to the question: what do some of the larger more exotic snakes eat? Some snakes primarily eat other snakes (the bandy-bandy of Australia). Some snakes eat mostly the eggs of other animals (see image above). And some of the larger snakes such as pythons and other constrictors will eat small mammals when young and begin to eat larger animals such as pigs, monkeys and deer as they mature.

Posted by the science guy for the best selling science toys of 2008 at Atomic Elephant Toy.

This is a bit of a humorous post as this question has made the rounds on the Internet for the last several years. The short answer is: goldfish are egg-layers and as such, they’re never considered pregnant. A female goldfish carrying eggs is said to be “ripe” but no ichthyologist would say she’s pregnant. You may have stumbled upon posts or trivia lists saying that a pregnant goldfish is called a twit, twat, twerp or whatever. They’re not.

Posted by the Triop Guy for Triassic Triops make great fishy gifts!

Some magnets are natural (lodestone and magnetite are naturally occurring), and some magnets are man-made. The magnets made in the laboratory are usually made of a mixture of iron, cobalt, nickel and other elements. The substances are magnetized by a couple of different methods. You could move a permanent magnet in one direction across the material to magnetize it. You could produce an electric current through coils around the substance to magnetize it. And some magnets can be made from a chemical reaction (ie., certain elements will become magnetic when reacting with oxygen).

Wikipedia gives a great description of exactly what a magnet is and how it works. Some of which I’ll summarize here. [source: Wikipedia] A magnet is a material or object that produces a magnetic field. This magnetic field is invisible and causes the most notable property of a magnet: a force that pulls on nearby magnetic materials, or attracts or repels other magnets. The structure of the invisible magnetic field of a magnet is made visible by the pattern formed when iron filings are scattered around the magnet, as in the graphic above.

A permanent magnet (also called a hard magnet) is one that stays magnetized. An example is the common magnets you put on a refrigerator door. Permanent magnets occur naturally in some rocks, particularly lodestone, but are now more commonly manufactured. A soft magnet (also called an impermanent magnet) is one that will gradually lose its magnetization. Soft magnetic materials are often used in electromagnets to enhance (often hundreds or thousands of times) the magnetic field of a wire that carries an electric current and is wrapped around the magnet; the field of the soft magnet increases with the current.

Posted by The Science Guy for the best selling science toys of 2008.

The Bubonic plague is a disease of the lymphatic system caused from the bite of an infected flea. The fleas are often found on rodents and seek live hosts (such as humans) when their rodent hosts die. Once established, bacteria rapidly spread to the lymph nodes and multiply. Yersinia pestis can resist phagocytosis and even reproduce inside phagocytes and kill them. As the disease progresses, the lymph nodes can hemorrhage and become necrotic. Bubonic plague can progress to lethal septicemic plague in some cases. Bubonic Plague kills about 50% of infected patients within one week.

What most people reading this were probably searching for is actually the Black Death, a specific incident of a Bubonic Plague epidemic that happened in Europe in the 1340s. At the time of the breakout, the world’s population is estimated to have been about 450 million. The Black Death killed about 75 million, or roughly one sixth of the population on Earth. Compare those figures to today’s population and that would be the equivalent of over 1 Billion people dying from the breakout.

The name “Black Death” comes from the fact that the disease causes symptoms like spots on the skin that are red at first and then turn black. Other symptoms include heavy breathing, continuous blood vomiting, aching limbs and terrible pain. The pain is usually caused by the actual decaying, or decomposing of the skin while the infected person is still alive.

Posted by admin for the best selling toys of 2008 at Atomic Elephant Science & Toy Co. For another interesting read, check out their list of the 10 deadliest insects of all time.

No one person is considered to have discovered Mars. As it is very bright in the night sky, it has been visible since the first humans gazed up to the heavens. What we do know is that it was named after the Roman god of war- presumably because of its red color which may have reminded our ancestors of blood.

1659: Christian Huygens discovered the dark spot located in the boundary between the northern lowlands and southern highlands of the planet. It was later called the Syrtis Major.

1877: Astronomer Giovanni Schiaparelli discovered what he believed to be several lines crossing one another. He claimed they were water canals made by intelligent creatures.

1877: Astronomer Asaph Hall spotted the two moons and named them Phobos and Deimos (fear and panic). He named them after the mythical horses that pulled the chariot of the Roman god, Mars.

1971: Mariner 9 returned images of Martian volcanoes and canyons. It discovered Olympus Mons, a massive volcano towering over 15 miles above the surface. Mariner 9 also found evidence that water once flowed on Mars. There were no sightings of Schiaparelli’s famous canals.

1975: Viking I and II spacecraft landed on Mars to study its surface. They analyzed the rocks and soil of the planet while providing us with information about its atmosphere and weather patterns.

Source: Wikipedia and the University Corporation for Atmospheric Research. Posted by the Science Guy for the best selling toys and childrens’ telescopes and astronomy toys.

As the child’s eyes are exposed to light (as they weren’t in the womb), the light then triggers the cell to start reading the gene. But it can take a while for the cell to ramp up to the final levels of pigment. That is why so many babies have blue eyes for their first months of life. Usually by their first birthday a baby’s eye color has settled in, but sometimes the iris doesn’t make enough melanin until about 3 years of age.

A nice description from About.com follows: “An infant’s eye color is determined by a substance called melanin. Melanin is a dark pigment contained in the iris, the structure that controls how much light is allowed into the eye. The color of the iris is determined by the amount of melanin in the iris. Light eyes have very little pigment, whereas darker eyes have a lot. In newborns, the pigmentation process of the iris is not yet complete. Babies with darker skin are usually born with dark eyes that stay relatively dark. Iris color in lighter-skinned babies is usually a blue or bluish-gray color at birth, then change as they grow. Melanin production changes during the first year of life, usually resulting in a darker, deeper eye color.”

Sources: Understanding Genetics at TheTech.org. Posted by admin for the science and educational best selling toys.

More about the Virginia Opossum [source: Wikipedia]

It is the largest member of its genus, family and order and is the largest of the opossums. They are typically 15–20 inches (38–51 cm) long and weigh between 9 and 13 pounds (4–6 kg). Their coats are a dull grayish brown, other than on their faces, which are white. Opossums have long, hairless, prehensile tails, which can be used to grab branches and carry small objects. They also have hairless ears and a long, flat nose. Opossums have 50 teeth and opposable, clawless thumbs on their rear limbs.

Posted by the science guy for the best selling toys of 2008.

Inland taipans are also called fierce snakes and can grow up to 10 feet (2.7 meters) although half of that is the norm. This snake changes color according to season. They range from dark brown to straw colored during the year but at winter they go darker and in the summer they go lighter.

Taipans hunt mammals so their poison can knock out warm-blooded, fuzzy rodents and animals, including humans. In a single strike (one bite) the venom can quickly paralyze a small animal or wipe out several adult humans. As the poison spreads, the victim will encounter headaches, nausea, vomiting and stomach pains. Sometimes there are convulsions and in extreme cases, coma.

If that’s not bad enough, the poison eats away at muscle tissue. Urine from the victim turns reddish-brown as their muscles deteriorate and pass through the kidneys. Internal bleeding is a major problem from taipan bites. The poison also prevents blood from clotting so the bite continues to bleed. This can cause internal hemorrhaging, especially in the brain. All this sucks for the bite victim but it’s great for the snake who only has to wait for its prey to stop convulsing before enjoying dinner. Taipans rarely attack humans, except in self-defense, so as long as they are left alone, humans will be too.

Source: Kidzworld.com and posted for the best selling toys of 2008 at Atomic Elephant Science & Toy Co.