They can all travel through empty space
Answer: A Fixed Action Pattern
Explanation:
A fixed action pattern is an ethological term and off course a natural activity pattern that causes animals to act in a specific behavior pattern distinctive to their species. It is a pattern that is relatively unchangeable within the species and usually ends even when it is interrupted. You can say that, it is innate releasing mechanism or network where sign stimulus exists, once released from neural network; fixed action pattern leads to completion as well.
Studying evolutionary relationship among organisms
