As a frugal old Yankee, I've found a means of dealing with FTR's (f'ng tree rats) that is humane, easy and CHEAP! FTR's tend to turn me into a Cranky Yankee.... Fill a 2 liter soda bottle ~3/4 full of water. Add one raw scrambled egg to the water, replace the cap and shake well each day for a week. Surprisingly, this mixture produces little or no gas. After one week, I usually dip a little of the mix onto pieces of paper towel, and either anchor it in a pot to protect it, or the strips can be hung on the branches of vulnerable flowers, vegetables, bulbs, etc. The scent is more obnoxious to animals than it is to humans. The only drawback is that it needs to be re-applied almost every day, especially after rain. Let me know how it works for you!