Simply put, bilateral symmetry involves the perspective of the sagittal plane (Divides body into right and left halves), and entails two fairly symmetrical, mirror images of the two halves of the body. This concept is perfectly demonstrated by the beautifully colored parakeets, as seen above. Furthermore, typically found in bilateral symmetrical, the head is at the front end, due to the sensory organs being there, detecting the environment, so the body behind can react appropriately to the surroundings. Furthermore, how symmetrical a male is can determine whether if it finds a mate or not, as female barn swallows select for this trait. Moreover, most leaves of plants will be bilateral too, however it is imperfect as can be seen with the veins in the leave. As can be seen, bilateral symmetry is a unique trait, which has proven to be a helpful adaptation, and unique characteristic that some organisms possess.