In article x%PGj.5711$rb6.4621@trnddc01,
Robert Allison wrote:

My question is about rats. I have a shop that has been invaded
by rats and I am currently without a cat that catches mice and
rats. My old cat kept them at bay, but the new one just likes to
watch them, apparently.

Anyway, I have set out rat traps and I have shot 2 with my pellet
gun. The first night with the traps I caught 3 rats. After 3
more nights with reset traps and new bait, not a single rat.

I am wondering if rats learn to avoid traps after they see what
they do, or did I get them all the first night? I don't know if
I am just lucky and there were only five rats, or whether they
all left after realizing they weren't welcome, or whether they
have learned to avoid being seen and to avoid the traps.

Anyone know?

Don't know whether you've still got 'em or not, but if so...

Go to the hardware store and look for something called a "Rat Zapper."
It is an electrocution trap that runs on four AA batteries. Stare at it
for about a half hour, trying to bring yourself to pay $50 for a plastic
box with a metal floor and couple of dimes worth of electronics.

Pay the $50. Read the instructions. FOLLOW the instructions to the
letter, which include a few days of progressive acclimation. Kill the
whole clan, approximately one rat every ten minutes. After five or six,
they'll still be twitching and you have to replace the batteries.

For its efficiency at rat clan elimination, its worth $1000. Absolutely
amazing.