You imbue nonintelligent plants and bushes in a 20-foot radius with the ability to shriek loudly if a Small or larger creature enters the warded area. The creature can go unnoticed if it makes a successful Dexterity saving throw, but it must be a conscious effort at sneaking by the plants. The shrieking plants are audible up to a mile away. Once the alarm is triggered, the plants shriek for 30 seconds, then the spell ends. 

Other than the size minimum, the spell is entirely nonspecific. Any creature that meets the size criterion, such as deer, foxes, and children will set it off.