A stickleback male, having built a nest and forcing one or several females to lay eggs in it, protects it and at the same time behaves in the most curious way: either it swims around the nest, then, as it were, fancies it – jumps up to the nest, then dives, turns its head to the nest and, staying in one place for about 30 seconds, quickly and rhythmically moves its fins, directing water into the nest. If the male dies, then all the eggs will die. Why?
The male, with his movements, ensures the supply of oxygen to the developing eggs.
Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.