Most commonly displayed in cats, high-rise syndrome is when unattended animals are left in front of an open window. They are either distracted by outdoor sights (birds, fireworks, etc.), or a loud noise startles them causing them to jump out of the window.
"Most pets when they are brought inside apartments do not walk up the steps into the building, which means that they have no perception of how high up they really are. If there is an open window cats will often misjudge the height and just jump out," Gail Buchwald, senior vice president of the adoption center at the American Society for the Prevention of Cruelty to Animals, told the Voice.