Why Rats?

I'm not sure why God created rats. I know I can't stand them. Having lived in tropical parts of the world for 25 years, Martinique, Haiti, and the country of Miami, I expected to see them everywhere. I hated watching them scamper across the electrical wires onto the roofs of buildings. Finding purpose in the life of a rat... I'm struggling with that one. Imagine my surprise at discovering one in my garage, here, in the cool and comfy state of Washington! After packing lunches for school early this morning, I opened the door in the kitchen/family room into the garage, turned on the light, stepped onto the garage landing and before stepping down onto the concrete floor, noticed a rat calmly waddling across the floor toward the furnace. I didn't scream but I didn't actually enter into the garage either. Calling for my husband to do his manly duty, I went inside to finish getting ready for school. T informed me that the rat had moved slightly behind the furnace. Not good! He thought it had probably eaten the poison he'd left under the shed in the backyard and that it was dying because as he explained, he'd never witnessed a rat move so slowly. UGH! All day I thought of that rodent in my garage. I got home from school at least two hours before T but I didn't linger in the garage. Not me... I came into the house, firmly shut the door, and stayed busy. Later, T came home and finished the job of slaying the rodent who was somehow still alive. Gross! I find those critters to be disgusting. I sure hope it didn't leave any family members behind!