Because in order to breath they need to swim, so how would they sleep if they are always moving?
130762
Sleep is one of the last bastions of mystery that Science has yet to conquer. Despite several centuries of study, speculation, and debate, we still really don't know what sleep is or why we need to 'shut down' periodically. We know that all sorts of vertebrate animals – mammals, birds, reptiles, and at least some fishes – periodically enter a period of torpor characterized by a profound change in brain waves.\n\nBut when it comes to whether or not sharks sleep, we just don't know. There have been reports from all over the globe, including Mexico, Japan, and Australia, of sharks resting motionless in caves. These have been called "sleeping sharks", but I can attest that the eyes of these quiescent sharks do follow divers moving about in the caves with them, so they're definitely not asleep.\n\nIn his sweeping epic Paradise Lost, 17th Century English poet, John Milton, asked, "What hath night to do with sleep?" We know from sonic telemetry studies (the underwater equivalent of radio tracking) that at least some shark species -- such as the Reef Whitetip (Triaenodon obesus) and the Tiger Shark (Galeocerdo cuvier) -- are actually more active at night than during the day. Since schooling behavior is partially coordinated by vision, many other sharks are most active at dawn and dusk, when such prey is at a disadvantage. Studies such as these suggest that at least some sharks do not sleep at night.\n\nWe used to think that the Great White Shark (Carcharodon carcharias) was primarily active during the day. But it turns out that this is largely due to observer bias: humans tend to be diurnal rather than nocturnal, and it's very difficult to watch an underwater creature at night. Recent experiments by Peter Klimley using stationary telemetry pods placed along the bottom at the Farallon Islands, we have learned that White Sharks are quite active at night, when they probably feed primarily on bottom fishes. If these bottom fishes are sleeping when attacked, they're certainly in for a 'rude awakening'!\n\nBecause sharks rely on ram-ventilation -- that is, their forward swimming to push oxygen-bearing water through their mouths and over their gills -- this fact begs the question: do sharks sleep at all? Dolphins are conscious breathers, actually having to think about rising to the surface, opening their blowholes, and breathing. From Russian studies carried out in the early 1970's, we know that dolphins catnap in 2 to 3-minute stretches, actually shutting down one hemisphere of their brain at a time. From experiments carried out on a small shark called the Spiny Dogfish (Squalus acanthias), we know that the 'Central Pattern Generator' that co-ordinates swimming movements in sharks is not located in the brain, but in the spinal chord. Thus, it is possible for an unconscious shark to swim.\n\nThere is even a possibility that the sharks' fore, mid-, and hind- brain shut down in sequence, resulting in the shark equivalent of sleep-walking.\n\nI hope this answers your question.
515303
No such thing. We can give them lots of things to put them to sleep, but there is nothing to give them that will keep them from pinching our butts if we get too close to a "wild" one.
288746
One word answers are not possible. If your teacher wants single word answers she is a moron.\n\nBirds, snakes and humans breathe using lungs.\n\nFrogs breathe using their skin and their gills when they are young and using their skin and lungs as adults.\n\nFish breathe using their skin and gills and also commonly use their swim bladder, mouth and stomach to breathe with.\n\nThe same applies to movement. Humans can move by walking or climbing or swimming or riding or driving or a bazillion other methods.\n\nFrogs and snakes may swim, or walk or hop or burrow or climb depending on the species and where it is.\n\nBirds may swim or fly or walk or hop or burrow or climb depending on the species and where it is.\n\nThere simply are no single word answers to these questions.
97969
They are not getting enough sleep.\n\nSee these links.
629739
they dont have to breathe... They are super mutant changy people... They breathe as humans no Power rangers!
272685
yes they need oxygen and don't have gills like fist. Instead of lungs, Air usually enters the insect's body through valve-like openings in the exoskeleton.   These openings (called spiracles) are located laterally along the thorax and abdomen of most insects -- usually one pair of spiracles per body segment. there are tubes inside that transport the air to all the cells of the ant's body, branching off and getting smaller and smaller. Then air diffuses out of the tubes into the cells. The concentration of oxygen in water is FAR less than in air so when water gets into the tubes not enough oxygen is there to diffuse into the cells and the ants drown.\nPS. please don't put ants into a jar and wait for them to die!!!\nPPS. there is something seriously wrong with the person who did that!
140752
that is your body's reminder to you that you need to move!\n\nusually when that happens, there is a loss of blood circulation from that area, and it "falls asleep." it's a painful reminder sent to us by our muscle tissue that it needs oxygen!
567556
I think you mean gills.\n\nThere are artificial liquids available:\nLiquid breathing is a form of respiration in which a normally air-breathing organism breathes an oxygen rich liquid (usually from the perfluorocarbon family), rather than breathing air. It is used for medical treatment and could someday find use in deep diving and space travel. Liquid breathing is sometimes called "fluid breathing", but this is misleading as both liquids and gases are fluids.\n\nNanotechnology is be used to create respirocytes which act as artificial red blood cells and could allow you to hold your breath for 1-2 hours underwater.
584459
Hey Bro..... only in their dreams...( but they spout it as fact )\n\nI think they need a life....maybe they could 'evolve' one.
555007
Walking, or any other form of non-airborne locomotion - you'd have to swim through the air\n\nCooking would be a bit complicated, everything would have to be contained. And forget a bowl of cereal.  Solid food would have to be in chunks, liquids in a pouch.\n\nCleaning up afterwards would be tough - how do you keep the hot soapy water in the sink?\n\nThink of all the things that would have to be restained from floating around as you go about your daily business.\n\nSleeping might be a bit more comfortable though, as long as you're tethered so you don't bump into walls all night long.\n\nAll in all, it would be similiar to life aboard a non-rotating space station.
646031
yup it's absolutely ok to wake them up cuz it's hazardous for them...it woould mean problems with their heart...and u can even ask them to lie on their sides..that would lessen the snoring... =)) hope this helps!
263686
You can train yourself to do this.  First of all being physically exhausted helps but is not necessary.  Honestly all you need to do is go through the motions and your body will eventually catch on.\n\nI used to coach swimming AND party way to much, and when we went to swim meets I could lay down in a hallway and catch 15-30 minutes of sleep between events, while kids were running and screaming all around me.  \n\nWhenever you want to sleep, just find a place to lay down, set an alarm, get in a comfortable position, and close your eyes.  You probably won't sleep at first.  But your body will become more relaxed the more often you do this.  Eventually your body will understand you are trying to compensate for something and allow itself to slumber.  \n\nOne of the secrets is to set the alarm, and lay still, with your eyes closed until it goes off.  Without the alarm you will constantly be wondering how long it's been and you won't be able to relax.
638434
"I think it would be highly unlikely that spiders would crawl into a person's mouth or nose while they sleeping. For one thing we move around a lot while we are sleeping and this would deter a spider from even crawling on you, let alone enter any orifice, especially one which is wet and dark. Breathing through your mouth or nose would also deter a spider from entering and most house spiders are too big to fit into a nose in any case. Spiders, like virtually all arthropods, flee from breath. After all, there are lots of vertebrates that eat arthropods, and if you're an arthropod and something is breathing on you, it's not a good idea to stick around. \nFor a spider to get into your mouth while you're sleeping, (a) you must have your mouth open when you sleep, which is certainly not something that everyone odes, so there's a big chunk of people who can never swallow anything; (b) there has to be a wandering spider in your immediate vicinity, also something which--for most people in the civilized world, at least--is a fairly rare occurrence; (c) the spider has to either jump or fall into your mouth from a long distance, because they won't go near your mouth otherwise (they're not suicidal), and the odds are pretty astronomical of a spider randomly dropping into your mouth from the ceiling. \n\nThere is a story about humans eating eight spiders a year in our sleep without knowing it and that it was supposedly tested by filming people in their sleep for a year. It is hard to believe that a group of people in different sleeping situations would have been filmed for a year or more to validate this statement. It is possible for a spider to walk into your mouth and trigger the swallowing mechanism at the back of the throat and this could in fact occur on a rare occasion. It may even be true that there are a few people out there who have unknowingly eaten eight spiders in the last twelve months. This still would not make such a generalisation be considered as true. I certainly wouldn't lose any sleep worrying about spiders while you sleep!! "
211817
Basically by getting their feet wet.  Sometimes they will walk through wet grass, or step in a bucket of water first.
121622
It is due to natural selection. Those of us who can breath oxygen without suffocating survive and those who can't die.
387207
Dolphins have to be conscious to breath. This means that they cannot go into a full deep sleep, because then they would suffocate. Dolphins have "solved" that by letting one half of their brain sleep at a time. This has been determined by doing EEG studies on dolphins. Dolphins sleep about 8 hours day in this fashion. \n\nA dolphin's behavior when sleeping/resting depends on the circumstances and possibly on individual preferences. They can either:\n1. swim slowly and surface every now and then for a breath\n2. rest at the surface with their blowhole exposed \n3. rest on the bottom (in shallow water) and rise to the surface every now and then to breath.
89153
The answer is a combination of several factors.\n\nThe skin is designed so as to limit "wrinkling" while swimming. (hydrodynamics) If u look at the skin closely, they consist of placoid scales which r smooth in one direction (swimming direction), and rough in the other direction.\n\nSharks r seriously buffed up, which aids in generating work.\n\nFins stabilise the body to prevent it from swimming upside down or in a circle\n\nThey belong to the chondrichthyes... cartilaginous fishes. This skeletal system is lighter than boney frames and allows for greater flexibility. Both characteristics COULD help in swimming. (There r, however, many fast marine animals with boney frames such as the dolphin or swordfish).\n\nThe tail is the main propulsion force. Which works in coordination with it's respiratory and circulatory system. As water passes over the gills, the lamellae r oxygenated, and at the same time release waste products (co2). So, if the shark swims slowly, the respiration rate decreases... and if he doesn't swim at all, he suffocates. I guess sharks swim fast because they have to. Haha. I hope that's helpful.