Neither ostriches, or flamingos bury their head in the sand.
Flamingos do not actually bury their head in the sand. It is a myth. Some also say that ostrich bury their heads in the sand, but this is also a myth.
Answer 1: yes when they sleep Answer 2: Answer #1 is a myth. Ostriches have never been documented to ever stick their heads in the sand either when sleeping or when frightened. How are they going to breathe if their heads are in the sand when they sleep? Let alone be able to hear any predators sneaking up on them. You can't hear very well when you have your head in the sand in comparison with having it tucked under your wing. So the answer to the original question is: they don't.
Ostriches do not actually bury their heads in the sand. This is a myth. Ostriches lower their heads to the ground to eat or inspect something, but they do not bury their heads in the sand as a form of hiding or defense.
Ostriches do not actually bury their heads in the sand. This is a myth. Ostriches may lower their heads to the ground to eat or inspect something, but they do not bury their heads in the sand out of fear or to hide.
Emus do not actually bury their heads in the sand. This is a myth. Emus are curious birds that may lower their heads to investigate something on the ground, but they do not bury their heads in the sand out of fear or to hide.
yes
No, ostriches do not actually bury their heads in the sand. This is a myth. Ostriches may lower their heads to the ground to eat or inspect something, but they do not bury their heads in the sand as a form of hiding or defense.
No, ostriches do not actually bury their heads in the sand as a defense mechanism. This is a myth. Ostriches may lower their heads to the ground to eat or inspect something, but they do not bury their heads in the sand when they feel threatened.
No, ostriches do not actually hide their heads in the sand as a defense mechanism. This is a myth. Ostriches may lower their heads to the ground to eat or inspect something, but they do not bury their heads in the sand when they feel threatened.
No, ostriches do not actually bury their heads in the sand as a defense mechanism. This is a myth. Ostriches may lower their heads to the ground to eat or to check their nests, but they do not bury their heads in the sand when they feel threatened.
Ostriches do not actually bury their heads in the sand. This is a myth. Ostriches may lower their heads to the ground to eat or inspect something, but they do not bury their heads in the sand out of fear or to hide from danger.
No, ostriches do not actually bury their heads in the sand. This is a myth. Ostriches may lower their heads to the ground to eat or inspect something, but they do not bury their heads in the sand to hide from danger.