rat poison
ratsbane

Heard about a new rat poison on the market.

Like as not get beat for my money or they slip me rat poison.

On her third try, at 45, she killed herself by swallowing rat poison.

Why didn't he just come over to my house and feed me rat poison?

Better to store the rat poison at cousin Betty's house.

And there were little dishes of rat poison set around.

He had injected himself with what turned out to be rat poison.

More to the point, they'd rather eat rat poison than be part of his.

"So they go through a lot of rat poison, these rats do."

That was where he kept the rat poison, too.