The rats take them back to their nest have a feast then get seriously ill over the next few days.
Rats in ceiling cavity.
Unfortunately i have had a decomposing rat in my attic.
Go to bunnings and get some of those blue wax rat bait blocks.
The man hole cover has been examined resealed and thames water have also had a look to see if there are any cracks in the pipework they found nothing.
If your home has no crawl space or attic space and the rats are in the tiny area between shingles and drywall you will.
When a rat dies in your cavity wall it will decompose.
Rat teeth leave ragged holes in wood drywall and plastic.
Ceilings and the roof which provide a chance to set traps.
If you have rats in the ceiling walls or attic of your apartment you may find evidence of this behavior.
Rats can chew their way through.
Set traps inside a void between ceiling.
Set traps inside any drop ceilings and at points like plumbing and heating penetrations where mice can exit the ceiling in the same way as in step 2.
All holes and as much of the cavity walls in the extension have been filled so that they cannot travel up the cavity walls.
There is one very good reason why you do not want rats in the cavity walls and it is the same reason why you should not use rat poison.
Best part is they leave the nest your house to find water.