Hi I have taken loads of tree rats by using peanut butter smeared on a tree stump,they have to lick it rather than just grab say a peanut and run also been elevated on the tree stump can give you a better shot than on a tree trunk or amongst undergrowth.I use crossman verminpell at about twenty yards, head shot is a must, if you lung shot em they ****** off and you will probably never find them leaving them to die slowly.
ONE SHOT ONE KILL !!!!
Hope this helps all the best Phil