Sorry if it was mentioned above, but I am going to bed soon and didn't want to read through all the replies.

I used to have a problem wth mice eating my tulip bulbs. What I did was start planting cloves of garlic all around my planted bulbs.

Make it as stinky as possible - i.e. cut the cloves of garlic open! If you start off with a large clove of garlic, you can cut it into 3 chunks which, when strategically placed, was enough to save one tulip bulb. You must also deal with the stalks of the garlic shooting up in your garden, but they are not so ugly, so I never minded.

After cutting and planting all that garlic, you will have stinky, garlic fingers, but you can get the smell off of your fingers with lemon juice.

I don't think this method harms anyone in any way.

After tulip season finished, and the lawn mower had been passed over the remains of the tulip bed, there was a strong garlic aroma throughout the garden.