Meintest du becker?
Portugal is the westernmost point of Europe and lies on the west coast of the Iberian Peninsula.
Comeback critters See how animal species in trouble have come back from the brink
Female black widows are shiny black, with a red-orange hourglass pattern on their abdomen. Male black widows are not black, but brown or gray with small red spots. Black widows are poisonous arachnids—animals that have a skeleton outside their body, a segmented body, and eight jointed legs. They are not insects. Their deadly poison is said to be 15 times stronger than rattlesnake venom. Black widows use a silk-like substance to weave tangled-looking webs, typically close to the ground in covered or dark places, such as near drain pipes or under logs. The female hangs upside down in the web to await her prey, exposing her bright markings as a warning to potential predators. The black widow senses vibrations to the web. When an unlucky intruder gets trapped, the spider immediately begins weaving its glue-like webbing around it. Insects such as flies, mosquitoes, or even larger prey like grasshoppers are typically caught. Once captured, the black widow injects its victims with poison, paralyzing them. The tips of the black widow’s legs are coated with an oily substance that prevents the black widow from getting caught in its own web. Adult male and female black widows live solitary lives, meeting only to breed. The female black widow lays approximately 200 eggs. The eggs incubate for some 20 days in a small, round papery sac that’s attached to the mother’s web. After hatching, the baby spiders stay in the cocoon for up to one month. Three species of poisonous North American spiders carry the common name black widow under the genus Latrodectus. Each species occupies a distinct region of North America, as their names suggest: Eastern black widows (L. mactans), northern black widows (L. variolus), and western black widows (L. hesperus). These three species have very similar physical and behavioral characteristics. The name “black widow” comes from the female’s habit of eating the male after mating.
The female black widow is approximately 1.5 inches (38 millimeters) long. The male is about half the female’s size.
The black widow is prey for birds and other spiders. Although poisonous, the black widow is not considered aggressive unless threatened. In fact, the male black widow is reclusive and hardly ever seen by humans. While the black widow’s poison is rarely fatal to humans, it can cause severe pain and nausea.
Comeback critters See how animal species in trouble have come back from the brink
Egyptologist Chris Naunton unwraps some secrets about what it’s like to study ancient Egypt.
things while he was king, and after he died, people tried to change everything back
The Egyptian who proved women could be powerful pharaohs
She sponsored one of Egypt’s most successful trading expeditions, bringing back gold
Dive into the wild world of sharks with the Nat Geo photographer and Explorer Brian Skerry.
upward at a fast sprint, burst out of the water in a leap called a breach, and fall back
Russia, the largest country in the world, occupies one-tenth of all the land on Earth.
Russian forces remained in Crimea to keep Ukraine from taking it back.
The woman who helped fight for women’s right to vote
But still she didn’t back down.
Grassland habitat facts and photos
buds of grasses grow underground, they aren’t damaged by fire and therefore grow back
Wolves live in groups called packs. A pack is a family of 7-8 wolves with a mom, dad, and offspring. The wolves‘ communication skills are very important to the pack’s survival. Wolves work together to hunt, raise their young, and protect their territory. Wolves communicate with more than howls. They whimper and whine, growl and bark, yelp and snarl. They also use scents produced by their bodies to communicate. A wolf’s sense of smell is 100 times stronger than a human’s. One source of scent is urine, which they use to mark territory and to tell other wolves in their own pack where they are. Another way wolves communicate is through body language. If a wolf feels confident, it will approach another wolf with its head and tail held high and ears perked up. If you saw a wolf slinking toward another with its body lowered, its tail between its legs, and its ears flattened, you’d know it was approaching a dominant animal. When a pack of wolves does howl, it can be heard from ten miles away. The howl is used as a way to call to another pack or warn of danger. Each pack has a unique howl, and while they don’t howl at the moon, wolves howl more when the moon is full and bright. When a wolf wants to play, it prances about happily and bows—lowering the front of its body while its rump stays up in the air with its tail wagging. When its angry, a wolf may furrow its forehead, show its fangs, or growl. A wolf’s body language may remind you of another animal: a pet dog. Wolves and dogs are closely related, and the ways they communicate are similar. Young wolves stay in their parents‘ pack for at least two years before some of them take off to join other packs or to start their own. They may stay close to their parents or go far away. Wolf pups play a lot as they’re growing. They leap and pounce, chase and wrestle, play hide-and-seek and tag—a lot like you do! A new wolf couple will produce one litter of pups every year. Just like a human older brother or sister looks after its younger sibling, the older wolf offspring care for their younger brothers and sisters by finding them food. In some areas, gray wolfs are classified as endangered, but in most places, they are seen to have healthy population numbers.
Comeback critters See how animal species in trouble have come back from the brink
The future is here! Check out eight of the coolest new bots coming soon to a library, hospital, or home near you!
Whether you’re in need of a back massage, a weather report, or even a pet, robots
