Why do mammals require sleep?
356089
Our body uses sleep for extreme brain activity.  It goes through all of the happenings of the day and records and categorizes them.  It decides the lessons learned (as in, if you got bit by a large green bug..you will now avoid large green bugs) and helps maintain the learning process.\n\nWithout adequet sleep, you will often not remember the events of the last few days as well, and being that you did not have time to process the last events, you will have difficulty concentrating on new ones.\n\n\nThat and its fun.
622847
Sleep is the regular state of natural rest observed in all mammals, birds and fish. Sleep is not actually "unconsciousness," but rather, it is a natural state of rest characterized by a reduction in voluntary body movement, decreased awareness of the surroundings, an increased rate of anabolism (the synthesis of cell structures) and a decreased rate of catabolism (the breakdown of cell structures). Therefore, since consciousness is literally the awareness of the surroundings, being asleep is just an altered state of consciousness, as opposed to being unconscious. It is heavily influenced by circadian rhythms and by hormonal and environmental factors. Sleep performs a restorative function for the brain and body as evidenced by the myriad symptoms of metabolic dysfunction that result when animals are deprived of sleep.\nThe function of sleep in health and in disease is being increasingly studied in specialized sleep laboratories throughout the world. Not only insomnia, but more recently elucidated sleep disorders such as sleep apnea and narcolepsy are evaluated in such facilities. The increasing prevalence of sleep disorders is likely to be a function both of more sophisticated diagnostic tests and the disruption of the normal day-night cycle in modern societies.
1580
Nobody knows for sure; however, there are many theories.  Below is a very plasable one:\n\nJerome Siegel, of the University of California in Los Angeles, along with colleagues elsewhere, has suggested a third possibility. Writing in a special review of sleep in the current issue of Nature, Dr Siegel says that it may be related to defence against oxidative stress. Smaller animals have higher metabolic rates, and this results in the generation of higher levels of small, highly reactive molecules such as free radicals. Studies on rats show that when they are deprived of sleep, their oxidative stress increases. Dr Siegel proposes that animals with higher metabolic rates need more sleep to interrupt and protect against this kind of oxidative damage, as well as repairing any damage done.
442542
It happens to the best of us. I think it is because they are so inactive during sleep, they need time to "wake up" just like we do!
393378
You could try to provide environmental conditions similar to the ones in their natural habitat. Some fish are nocturnal and will be sleep-like in the presence of daylight, or viceversa. \nThere are also anaesthetics for fish, such as clover oil or MS-222. You should consult an animal physiologist before administering them, though.
311429
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.
1009933
We need to sleep because we need to let our musles have a break and to give our brain a break also we need to recharge for the next day. We need sleep so our body's can funtion right and so our brain can slay alert.
221264
The record is something like 12 days or so by a kid. Everyone will eventually succumb to the need to sleep but when in the question. They cannot figure out why our body needs sleep and one one has ever died from a lack of it. Some theorize that we sleep because back in the day humans needed to stay in at night to avoid getting killed by nocturnal animals.
680686
Animal studies have shown that sleep is necessary for survival. The normal life span of rats is 2-3 years. However, rats deprived of sleep live for only about 3 weeks. They also develop abnormally low body temperatures and sores on their tails and paws. The sores probably develop because of impairment of the rats’ immune systems. \n\n\n\nIn humans, it has been demonstrated that the metabolic activity of the brain decreases significantly after 24 hours of sustained wakefulness. Sleep deprivation results in a decrease in body temperature, a decrease in immune system function as measured by white blood cell count (the soldiers of the body), and a decrease in the release of growth hormone. Sleep deprivation can also cause increased heart rate variability.\n\nFor our nervous systems to work properly, sleep is needed. Sleep deprivation makes a person drowsy and unable to concentrate the next day. It also leads to impairment of memory and physical performance and reduced ability to carry out mathematical calculations. If sleep deprivation continues, hallucinations and mood swings may develop.\n\nRelease of growth hormone in children and young adults takes place during deep sleep. Most cells of the body show increased production and reduced breakdown of proteins during deep sleep. Sleep helps humans maintain optimal emotional and social functioning while we are awake by giving rest during sleep to the parts of the brain that control emotions and social interactions.
368677
maybe because they are less agile than that of a smaller animal there by needing only to consume such quantity of food, and also bigger animals has the ability to conserve energy in their body......i guess
164877
they are mammals so they breathe air
991
Koalas rest motionless for up to 20 hours a day, sleeping the majority of that time due to a low metabolic rate.
256741
Bony fishes don't have eyelids. Cartilaginous fishes (sharks and rays) have a more or less developed lower eyelid thay may or may not have a nictitating membrane (a transparent extra eyelid). In any case, sharks close their eyes for protection when they bite, not for sleeping. And the upper eyelid is just a tegumentary fold.\nSee a nice illustration here (from Elasmoworld):\nhttp://www.elasmoworld.org/biology/anatomy/shark/external/diagrams/eye.gif\n\nFish sleep with their eyes open (the definition of fish "sleep" is not completely agreed upon, some researchers speak of "sleep-like behavior").\n--------------------\nKamannchie_girl, what do whales have to do with the question? You'll only confuse people if you mix whales with fish.
668039
I am currently taking Modafinil and I would say that it will definitely not allow you to get rid of the need to sleep.  It only works for about 15 hrs, and sometimes doesn't seem to work at all and I wonder if some are sugar pills (highly unlikely).  You need to sleep to allow your body rest to repair itself. Your immune system also gets significantly weaker when you are deprived of sleep. The drug insert claims that when they kept rats constantly awake with drugs, they soon died of massive blood infections. If you don't sleep, you will soon be sleeping forever.
675372
Each has it's own methods.\nSurprisingly undergrowth and thick forest provide excellent cover. I have seen pigeons tough it out by hunkering down in a flat field, but suspect that is just the normal sleeping behaviour.\nAny creature that has it's own territory will have it's own safe places (holes, nests, caves, thick bushes, etc.), migrant species may move out of the danger area.
331028
The Need for Sleep \n \nSleep Is a Basic Human Need\nSleep is a natural part of everybody's life, but many people know very little about how important it is, and some even try to get by with little sleep. Sleep is something our bodies need to do; it is not an option. Even though the exact reasons for sleep remain a mystery, we do know that during sleep many of the body's major organ and regulatory systems continue to work actively. Some parts of the brain actually increase their activity dramatically, and the body produces more of certain hormones.\n\nSleep, like diet and exercise, is important for our minds and bodies to function normally. In fact, sleep appears to be required for survival. Rats deprived of sleep die within two to three weeks, a time frame similar to death due to starvation.\n\nAn internal biological clock regulates the timing for sleep. It programs each person to feel sleepy during the nighttime hours and to be active during the daylight hours. Light is the cue that synchronizes the biological clock to the 24-hour cycle of day and night.\n\nProblem Sleepiness Has Serious Consequences\nSleepiness due to chronic lack of adequate sleep is a big problem in the United States and affects many children as well as adults. Children and even adolescents need at least 9 hours of sleep each night to do their best. Most adults need approximately 8 hours of sleep each night.\n\nWhen we get less sleep (even one hour less) than we need each night, we develop a "sleep debt." If the sleep debt becomes too great, it can lead to problem sleepiness – sleepiness that occurs when you should be awake and alert, that interferes with daily routine and activities, and reduces your ability to function. Even if you do not feel sleepy, the sleep debt can have a powerful negative effect on your daytime performance, thinking, and mood, and cause you to fall asleep at inappropriate and even dangerous times.\n\nProblem sleepiness has serious consequences – it puts adolescents and adults at risk for drowsy driving or workplace accidents. In children, it increases the risk of accidents and injuries. In addition, lack of sleep can have a negative effect on children's performance in school, on the playground, in extracurricular activities, and in social relationships.\n\nInadequate sleep can cause decreases in\n- Performance\n- Concentration\n- Reaction times (important when driving)\n- Consolidation of information learning\n\nInadequate sleep can cause increases in\n- Memory lapses \n- Accidents and injuries \n- Behavior Problems \n- Mood Problems \n- Signs of sleep disorders
19895
Well mammals hold their young in their wombs for a time (fetus development.....you should know you're a mammal) Females breast feed their young, they mother them, and basically show them the basic instincts they would need to surivie alone. But, all this depends on which mammal you are asking on-some mothers don't do all this with their young