Rats have been an issue here. They haven't made it into the grain, but they had decided that the roof cavity makes a great home.
They didn't touch the ratsack. So we bought some single feed Talon blocks. That did kill two rats.
Poison is a worry as the dog or cat may catch and eat a poisoned animal. Also, dead rats in the roof cavity stink, and even worse if they drop into a wall cavity.
The best result has been traps baited with bacon rind or beef sinew. The bait dries on the trap trigger and shrinks. This is hard for them to remove without triggering the trap. Do tie the trap with a bit of string to something. A few times, the trap has only caught the animal by the tail or a leg, and they then manage to drag the trap off.
Caught two in one trap one evening.
The funniest was the young rat that decided to go down the clothes dryer vent from the ceiling cavity. It couldn't climb back out. The cat was trying very hard to work out how to get into the clothes dryer.
Total over the last two weeks is seven half grown and one full grown rat.
Both the dog and cat have been doing a good job on any mice. If we find that they have an area staked out, we shift things around and usually the dog or cat come up trumps.
The brown snake that was here two weeks ago, right near the dining room door was really not wanted.