Silent Killer!

In chicken run in the first night a
Giant Rat killed! Bait Marsstückchen (bonded well)
and Schinkenwürfelchen of Norma!
The cat of my daughter having tried but are not hard to get!
In order to be able to establish the case (because of the cat), I had to do a self-test before the family!
(Question: Which fingers you need at least?)
I have it survived, and the finger is still there!
I will not tell you what it was!