There is nothing like a good night's sleep to set you up for the day ahead. Many of us take sleep for granted and never stop to think about sleep any more than popping our heads on the pillow each night. For others sleep is their life. Many scientists and animal behaviourists have devoted their waking hours to the study of sleep and its effects on both humans and animals. Research, carried out mostly in the last 25 years, has resulted in a superabundance of sleep facts - we have chosen a few of the more interesting ones to share.

After remaining awake continuously for 18 days, 21 hours and 40 minutes, the winner of a rocking chair marathon suffered hallucinations, paranoia, blurred vision, slurred speech and memory and concentration lapses.

A study in 1998 showed that shining a bright light onto the backs of human knees had the ability to reset the body's circadian rhythm. Scientists are still searching for an explanation to this phenomenon.

Sleep apnoea poses a significant risk to health, increasing the risk of heart attack and stroke. Approximately ten percent of snorers suffer this disorder, stopping breathing as many as 300 times each night.

Some animals have the ability to keep half of the brain awake while the other half sleeps. Dolphins use this skill to maintain their breathing, while ducks remain alert for predators while they rest.

Rapid Eye Movement (REM) dreams that occur in deep sleep tend to have random and inexplicable plots, while non- REM dreams are far less interesting - a possible explanation for why elephants remain standing for non- REM sleep, but need to lie down for REM sleep.

Source abc.net.au