Why are most animals such light sleepers compared to humans?
I cant even tip-toe past my dog when its sleeping without waking him. However, i can sleep through a thunderstorm no problem.
I have read in an early 1900s “ANimal Intelligence” book that when ants go to sleep they are in a state which resembles death. They can get carried around, kicked around, whatever, and wont awaken until they are rested.
Has there been any studies into this?
I haven’t read any studies but presume the light sleeping is related to their survival instinct to maintain alertness in the event of possible approaching predators.
Yeah, most animals are considerbly lower on the food chain.
Some aquatic mammals and birds sleep with only half their brain at a time, alternating with one eye open and alert to their surroundings. That’s pretty efficient.
I used to sneak in and watch my aquarium fish sleeping. Very weird.
Humans in hazardous environments quickly turn into pretty light sleepers. The ones that don’t & mistake incoming artillery for thunder don’t last long.
I think some sleep behavior is related to how secure an animal feels, too. My dogs sleep DEEPLY when in bed with me- I suppose they see me as alpha and figure whatever happens, I can handle it. Last night was VERY stormy, and I was awakened several times by thunder and the storm sirens. The dogs? The only time any of them woke up was when I got up to pee and then they all piled out of bed to follow me to the bathroom.
Several years ago, we had a pretty intense earthquake, woke me right up. My dogs and cats slept thru it, and actually seemed annoyed when I woke them up, by getting out of bed.
Dogs might not be the best example – keep in mind we basically “hired” dogs to be light sleepers (among other things).
I do not notice this in my two dogs and two cats. They usually sleep like logs and sometimes I have a hard time waking them up! We live in a building with multiple apartments over a block of shops in a busy commerical area with three bars on the street, so they are well-used to constant unusual noises.
I consider myself a deep sleeper, and don’t wake for severe thunderstorms etc, but I will wake with a start for certain small noises that communicate ‘danger’. I’ve been woken by a mouse rustling paper in the next room, and by someone tapping as softly as humanly possible on my front door (a room and a hallway away from my bed).
Similarly, my dogs are very attuned to certain noises - storms, huge crashes outside, and people stampeding and screaming in my building don’t even get an ear flick, but if someone knocks on my door or they hear a dog go panting and jingling down the sidewalk outside, they’ll leap from a sound sleep into ‘guard mode’.
My cats rarely seem to notice any noise that happens more than 2 feet away from them - unless that noise is me opening the fridge or making other sounds they associate with getting fed.
Also, I have a tiny two-room apartment, so they don’t usually bother to follow me around it, but if I had a house, they would probably rouse and follow me from room to room. It’s easy for them to sleep deeply knowing I’m not going anywhere and they won’t miss anything.
I had a nocturnal Tanganyikan biotope that I illuminated at night with a red light. It was neat to see the eels active and hunting while their tankmates were sleeping under their ledges and in their dens.
I’m not sure that animals do sleep more lightly than humans…
Animals have much better senses than humans. As any hunter will tell you, it’s damn hard to creep up on an animal when it’s awake. So there is no reason to think it would be harder when they are asleep. In general any noise that would attract your attention while awake will also wake you from sleep. The same is also true of animals, the only difference being that the noise threshold is far lower. Tiptoeing past a human is unlikely to attract their attention when they are awake, whereas it will a dog.
Animals mostly don’t “sleep” sleep. Most of what they do is catnapping, which is very light sleep. Dogs and cats sleep about 16 hours a day in that manner, very little of it is “real” sleep. A human in that state is also a very light sleeper because you are hardly asleep.
Animals certainly do sleep deeply some of the time, mostly when they are genuinely tired from exercise. In that state they are just relatively oblivious as a human in deep sleep. I have several times crept up on sleeping animals, both wild and domestic. Once I *accidentally *crept up on a sleeping fox, which was truly astonishing. You mostly don’t see sleeping wild animals because they hide when they sleep, but with domestic animals it’s quite easy to sneak up on them if they are sleeping deeply.
I think bears and other hibernators sleep pretty deeply at times.
:dubious: That seems like a reckless overgeneralization. I do not think many animals (clearest exception: birds of prey) have better eyesight than humans, and our hearing is actually pretty good too, especially in terms of the range of complex sounds (such as phonemes) that we can distinguish (but I think we are fairly well up there even just on aural sensitivity, even if dogs do have us beat).
Our hearing is vastly inferior to that of most mammals, but our eyesight is unsually good (in daylight).