We have had a little rat bait under a slab in our plant nursery. After a couple of nights of the poison being consumed I set up my wildlife camera to see what is happening:
Here you can see 2 rats at the edge of the plant area. At times I think there were at least 3 of them. They were running about all over the plants but mostly going under the white slab (in the middle background) to get at the feed/poison.
So that night I put a larger container of poison under the slab and moved some of the plants to get a clear view. This is what I saw:
The rats were still coming and looking but not taking any of the bait. During the night they kept revisiting the poison but were not eating any. They seemed to be disturbed by the different containers so kept away from the poison.
Intelligent creatures!