What are some animals that do not require a lot of sleep?

I’m thinking that sharks and other fish don’t sleep as we define it.
Edit to add: And i think I remember reading somewhere that cats sleep around 15 to 20 hours per day.

@JilltheTooth: Do you suppose that cats sleep that much because they have ample opportunity or because their bodies actually need that much rest? I wonder if jungle cats sleep that much.

I think it’s an energy conservation thing, when they hunt they burn a huge amount of energy, but it’s quick. Probably you should send this to Syz…

Done!

Adult mayflys.

Albatross. They spend most of their time flying, so perhaps they nap now and then WHILE flying, but they don’t tend to land to sleep.
http://www.onlinemathlearning.com/animalfacts-albatross.html

http://ngm.nationalgeographic.com/2010/05/sleep/max-text

According to this article nobody can actually figure out why sleep is needed at all, but we do know that extreme sleep deprivation is fatal.

Also, apparently dolphins and mallard ducks are able to sleep with only half of their brain, while the other half remains aware.

Conclusion: sleep is weird.

@satyagraha Dolphins use half their brain because breathing is a voluntary action.

@KatawaGrey Interesting question, and one I don’t have much information on – I’ll have to do a little research. The only other type of animal that I would guess would be some of the small species that have incredibly high metabolic rates (some voles, the least weasel), since if they fail to feed for more than a few hours, they starve (although many of them are able to enter a sort of dormancy that allows them to survive rest periods).

According the this, giraffe sleep only 3–4 hours per day.