my experiential problem with flypaper, is that:
1. one has to be physically there, when the rat gets enmeshed. otherwise,
2. gagapang yan nang uni-unti, hanggang makawala. in the process, he will contaminate your floor with all that sticky and hard-to-remove goo.

i prefer the scientific method.
lay down some anticoagulant rat poison, so's he eats it and bleeds to death, usually in the open where it's brighter.