Halacha 3: a mole trap is susceptible; a mouse trap is pure because it lacks a receptacle and vessel form.
Question 4
A palm-branch pocket for fresh dates — when is it susceptible to impurity?
Halacha 5: susceptible only if one places fruit inside and can remove it normally. If one must tear or undo it, or intends to discard the pocket, it is pure.
Question 5
Benches set up in inns with detachable legs in holes — are they susceptible to impurity?
Halacha 11: any seat that is portable but its legs are not carried with it is pure. Legs affixed with nails make it susceptible.