Home made silencer for .22

I know it sounds bad but let me explain. I also know some won't agree, you don't have to I understand.

OK so I own dogs and they hate cats. My neighbors feed stray cats and it drives my dogs nuts at night. The cats stay away during the day but hang out just out of the dogs reach and on the hood to my truck. That's a no no here.
So now for the legal side. Its legal here to shoot a cat that has no collar, they are considered a nuisance. Now my reason for wanting to quiet the shot is because this will all go down at night, and I don't wish to scare or wake up the neighbors. No the gun isn't that loud but in the quiet of the night it will likely draw the attention of the other dogs around here causing more barking.
I also have traps set to capture these cats but the remaining ones are the ones that have not entered the trap.

 

Federal offense without a Class III license.

 

2 liter plastic bottle?

 

This thread will not go well...

 

I bet with a well placed shot this would do the trick.

http://www.gamousa.com/product.aspx?product=Whisper VH&productID=286

 

Did not realize it was a crime. Thanks this can be closed. I have reported it. Thanks for the info it was an oversite on my part.