This PIR sensor can be used for motion detection, either to detect human movement or pets. It works by taking a snapshot of the infrared signature of the room and gets triggered when it detects a change. Its pretty sensitive and is typically used in most intruder detection systems.

 It has a configurable trigger ON time as well as a configurable sensitivity, which allows you to set it such that it does not trigger for pets but does trigger for humans.

Specs

Supply voltage from 4.8V-20V

static current:<50uA

Level of output: high 3.3V/low 0V

triggered way:L not repeatable triggered/H repeatable triggered (default repeatable triggered)

Delay time:0.5-200s(adjustable)

Blocking time:2.5s(default)

Circuit board dimension:32mm*24mm

Angle of induction:<100 degree Cone Angle

Working temperature:-15C to +70C

Induction lens size: Diameter: 23mm (default)

2 x PIR sensors in this package ( $12.99 each )