Ceilings and the roof which provide a chance to set traps.
Rats in ceiling cavity.
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 you have rats in the ceiling walls or attic of your apartment you may find evidence of this behavior.
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.
Set traps inside a void between ceiling.
Rats in the ceiling can be difficult to trap and remove especially if your home is one of the few that lacks a proper attic.
Rat teeth leave ragged holes in wood drywall and plastic.
Best part is they leave the nest your house to find water.
All holes and as much of the cavity walls in the extension have been filled so that they cannot travel up the cavity walls.
You can put them in travel paths toss them in to ceilings or drop them down walls.
Rats can be heard at night in the kitchen and bedroom area.
Go to bunnings and get some of those blue wax rat bait blocks.
When a rat dies in your cavity wall it will decompose.
If your home has no crawl space or attic space and the rats are in the tiny area between shingles and drywall you will.
Unfortunately i have had a decomposing rat in my attic.