Yes.
Lying down.
Fish sleep on the ground.
Lying down.
Yes they can, and in fact a horse can only get REM sleep by laying down.
Lying down.
Standing up or lying down.
by lying down same as humans <3
because they're tired.
Sheep primarily sleep lying down, although they are capable of dozing while standing. They feel most comfortable and get their deepest rest when lying down.
Elephants do not lie down and sleep. They sleep standing. You know why? They are afraid ants might get into their trunks
It is theoretically possible for a human to sleep standing up, but it is not common or ideal. The body's sleep cycle and posture adjustments during sleep are optimized for lying down. Standing up to sleep can be uncomfortable and may not allow for the deep, restorative sleep that lying down provides.
Sleep, Slept, Sleeping