Inspect the flower box carefully for signs of rat activity. Soil piled around the base of the flower box from burrowing activities, damage from scratching or chewing, fecal material around the nesting site and well worn paths leading away from the flower box are all common signs of rat activity.
Place a fine layer of talcum power around the base of the flower pot. Look at the powder the next day to determine what direction the rat goes when scavenging for food at night. .
Bait a simple snap trap and place it in the vicinity of the infested flower box. Try to position it along the known path of the rodent. The best baits for rats vary based on the type of food the rat is feeding on around your home, but commonly used baits include sardines, peanut butter, whole nuts, bacon, raisins and grapes.
Inspect the trap regularly for signs of rat activity. Place talcum powder around the base of the rat trap to identify if the rat has found the trap. Rats are cautious animals and it may take them several days before they actually approach a snap trap and take the food.
Remove and dispose of rats as soon as they are trapped to prevent unpleasant smells around your home.
Remove the plants and soil from your flower box and line the inside of the planting container with hardware cloth to prevent future rat infestations. Replant your flower box and water thoroughly to re-establish a healthy, rat-free flower box.