"Piercing butterflies can be seen deeply, but dragonflies can fly slowly." The poem describes (a) the defensive behavior and migration behavior of these two insects, and (b) feeding.

Foraging behavior: it is the behavior of animals to obtain the food they need for survival through various ways.

Defensive behavior: In order to protect yourself, all kinds of behaviors to defend against enemy injuries are defensive behaviors, such as running away, playing dead, releasing odor, protective color, warning color, physical defense, etc.

Reproductive behavior: behaviors related to animal reproduction, such as nesting, courtship, mating, hatching eggs, feeding, etc.

Migration behavior refers to the long-distance round-trip migration of a certain bird regularly along a relatively fixed route between the breeding ground and the wintering ground in spring and autumn every year.

Pink butterflies deeply see butterflies feeding on pollen, which belongs to foraging behavior; Dragonflies fly slowly in the water, laying eggs, reflecting the reproductive behavior of animals.

Therefore, choose: d.