2 Answers

rat or mice baits are perfected to be a fed through poison which makes them very thirsty, and since most of the time their source of food is in your home, and shelter there, but they get their water outside your home.  They go out to drink, and die outside, usually.  They hemorrhage and bleed to death with internal bleeding.  A sure fire way to guarantee that they do die, and you get the body out of the house is the good old fashioned rat trap.  Snap traps may be gross, but they work, put one somewhere and bait it with the minimal of bait, less that what they can get on a lick, peanut butter is killer (pardon the pun).   Put a string on the trap, so they do not fall into wall cavities, etc. and you can pull it back, hopefully with a dead rat on it.  A good barn cat, or a terrier dog with good instincts, work well on farms, etc. but not in urban areas.  I owned a farm dog, a border collie, who once got into a nest of rats under an animal feeder at a feedlot, he killed 10 adult rats in less that a 2 min. time,   he grabbed and shook them breaking backs, grabbed and shook the next, till 10 were scattered dead!  I never saw a dog that good!