Which of the following is NOT mentioned in the passage as an advantage derived by birds that huddle together while sleeping?
Which of the following is NOT mentioned in the passage as an advantage derived by birds that huddle together while sleeping?
A. Some members of the flock warn others of impending dangers.
B. Staying together provides a greater amount of heat for the whole flock.
C. Some birds in the flock function as information centers for others who are looking for food.
D. Several members of the flock care for the young.