Why do frogs close their eyes when they eat?
A frog often retracts its eyes to help swallow its food. When a frog eats, it pulls its eyes down into the roof of its mouth. This helps force food down its throat.
Can cats see in color?
Cats can see in color, but they do not see all the colors that humans see. In cats, rods (cells in the retina which are responsible for black and white) largely outnumber cones (responsible for converting light into color). So, though cats do see in color, they have trouble distinguishing reds, oranges and browns which appear to them as differing shades of gray. Based on studies, purple, blue, green and yellow appear to be the strongest colors perceived by cats. Cats appear to see less saturation in colors, thus they do not see colors as intensely as humans do.
Cats have a light-reflecting layer that enhances their night vision. Thus, cats don't really need to distinguish colors as they can see even in the dimmest of lights, which is more important as they hunt for food at night.
Are there insects that can walk on water?
The water strider, sometimes called Jesus bug or pond skater, is one insect that can walk on water. Aside from a force called surface tension that pulls on the water's surface creating a very thin stretchy layer on the top, water striders have tiny hairs on their legs that allow them to walk on water without sinking. All six of the water strider's legs are covered with thousands of microscopic hairs that trap air, making the legs waterproof and thus increasing its legs' water resistance and its overall buoyancy allowing it to simply float and travel on water surfaces.
Why do koalas sleep so much?
Koalas are big sleepers and spend about 15 hours a day sleeping and another five hours resting. Since they only eat eucalyptus leaves which provide very little energy and nutrients, koalas sleep a lot in order to conserve their energy. They live in eucalyptus trees, where they are safe from predators, and there sleep all they want.
Do ants have skeleton? How much load can they carry?
Unlike humans, ants have their skeletons on the outside of their bodies (muscles attached internally), called exoskeleton. The exoskeleton serves as protection of the ant's entire body.
One amazing thing about ants is that they can carry up to 30 times their body volume and up to 50 times their weight.
How do fish breathe underwater?
Fish breathe underwater through their gills. Through their gills, fish extract oxygen from the water that they take in using their mouth. As they breathe in water through the gills, structures called gill rakers filter the water to sift out foreign particles. The water then flows across disc-like membranes of the gill filaments, called lamellae, where oxygen and carbon dioxide exchange takes place across the lamellae's capillary network. Fish must continuously pass new water over their gills to sustain a supply of oxygenated water and ventilate their gills.
Why do camels have humps?
Camels have humps as storage places for fat. This stored fat, which serves as their emergency food supply, is necessary for them to survive long travels through the desert where food and water are not readily available. When this food reserve is used up after a long, exhausting journey, the hump shrinks and becomes floppy. It however becomes firm and upright again once the camel has taken enough food and water (a camel can drink up to 20 gallons of water at a time).
How do fish float?
Many fish have an expandable sac (like a human lung), called swim bladder, that allows them to rise and sink in water. As the fish fill the bladder with air extracted from the surrounding water through their gills, they rise through the water. As they let the air out and deflate the bladder, they float lower down.
How can seals stay long in icy waters?
Seals are warm-blooded. This, and the thick layer of fat measuring to several inches beneath their skin, called blubber, insulate and help keep them warm in the coldest seas. Seals also have thick under and overcoats of fur, which they shed once a year, that protect their skin from icy waters.
Why do sharks have to keep swimming?
Sharks don't have swim bladders, so they have to swim and propel themselves forward to ascend and descend in the water. As they swing their tail back and forth, they are propelled forward and water is pushed around their fins creating lift that pushes them upward (sharks also have large, fat-filled livers that give them some buoyancy). If they stop swimming, they sink, also because they are heavy for their size and are dense with respect to water.
