REM sleep is also called paradoxical sleep because in this state, the sleeper is difficult to wake-up in spite of showing the brain waves associated with waking, hence the term paradoxical, as the state itself is somewha... More » Science Biology

Dogs dream during the REM phase of sleep, just like humans. There is evidence that they dream about their daily activities. They often twitch, vocalize and breathe differently while dreaming. More » Pets & Animals Pets Dogs

Most people can stop the problem of drooling in their sleep by changing their sleep position. Dr. Celite Kushida of the Stanford University Center for Human Sleep Research advises people with sleep-related drooling issue... More » Science Biology
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You do not swallow saliva in your sleep because facial muscles are relaxed. Most people wake up with saliva in their mouth, which is instantly swallowed once that person wakes up. While sleeping, people do produce saliva... More » Science Biology

A niche is a scientific term used to describe the relationships between a species and the elements in its ecosystem. It is determined primarily by the way a species reacts to environmental factors, such as food sources a... More » Science Biology

Scientists do not agree on exactly how new species form; they do not even agree on a single definition for the term “species.” Some suspect that new species form when a population of individuals becomes reproductively is... More » Science Biology