Theories have long existed to shed light behind the age-old question why we sleep, like the one which says sleeping conserves energy, while others also suggest that it consolidates our memories. At an average, humans sleep eight to 10 hours every day, bats and opossums for 18 to 20 hours, while elephants and giraffes for only three to four hours. But now, you have probably noticed that your dog sleeps twice longer than you do. And, you most probably worried over what you observed. In the end, you may end up thinking just why your dog is spending long hours sleeping on its crate ?

Take a look at the following facts to help you understand the underlying factors on your dog's extraordinary sleeping habit:

Since they are excellent predators, dogs conserve less energy, giving them the luxury of long sleep (approximately up to 16 hours) than humans. Dogs enjoy this unfair advantage over humans. Since they have more stored energy, dogs tend to slumber significantly longer than humans.

The sleeping hours of dogs are determined by several factors. The said factors are: pets' activities, health, age, and breed aside from environmental or weather conditions. Consider these:

-- Dogs who are treated as pets generally sleep longer compared to dogs who are doing different activities, and since dogs basically have fewer tasks and responsibilities than humans, they're expected to have longer sleeping hours.

-- Dogs with illnesses, undergo medications, suffer from depression, hypothyroidism, and senility doze off longer than expected.

-- Middle-aged dogs spend about 16 hours of sleep a day, while older canines sleep longer. This can be attributed to the fact that canines belonging to these age brackets have lesser or slower mobility compared to younger ones. Hence, they have the luxury of being idle. And idleness, like in the case of humans, is a perfect excuse for sleeping.

-- Canines tend to doze off more on sunny days.

Determining the desirable sleeping hours that your pet should only have every day is a hard task. It is due to the effects of the factors listed above. Thus, there can't really be a standard regarding dogs' sleeping hours because it is dependent on the above-mentioned elements.

Worry not if your pet slumbers longer than you do. Just make sure that it immediately reacts to sudden bursts of noise or other activities. Older dogs fall under a slightly different case as their failure to be alert may be caused by difficulty in hearing.

Should your pet display some weird deviations, experts say that you should take them to the nearest vet. Remember, though, that you should only subject your pet under an expert when prolonged changes in its sleeping habits take place. Take time to check if your pet showed signs such as sleeping at a higher or lower rate than the usual or is visibly lethargic-- shows signs of sadness, depression, aggressiveness, or a sudden change in weight.