Trapping is often the best way to remove rats from a home because it is precise, poison-free, and lets the technician physically remove each rat rather than leaving it to die in a wall. But trapping only works when the traps are the right type, placed in the right spots, and monitored over several days. That is where professional trapping pulls ahead of the snap traps most people scatter around the kitchen.
Rats are neophobic, meaning they are suspicious of anything new in their environment. A trap dropped in the open often sits untouched for days while the rats route around it. The pros who handle it read the signs, droppings, grease marks, gnaw damage, and place traps directly on the runways rats are already using, along walls, in the attic, near entry points, and bait them in ways that overcome that caution. Then they check and reset until the activity stops.