http://ca.news.yahoo.com/pets-notice...215405656.html

You might think it unlikely that this weekend's switch from daylight saving time (DST) to standard time could throw your cat or dog's busy schedule — eat, sleep, eat, sleep — off-kilter. But, as it turns out, some animals are so in tune with their owners' schedules that falling back an hour can cause our furry friends some confusion.

Just like humans, animals have their own internal clocks that tell them when to eat, sleep and wake up. This biological timekeeper, also known as circadian rhythm, is set in motion by natural sunlight. However, for pets this effect is minimized by the artificial environment they live in, where light comes and goes not only with the rising and setting sun, but most often with the flip of a switch.