I don't want this post to go to the dogs or anything, so just to show you my bark is worse than my bite, I'm sending you to this list of cat and dog idioms.
An idiom is a phrase that can mean either exactly what it says, or express an entirely different state of mind or activity. For example, the Japanese phrase "neko ni koban" means "giving gold coins to a cat". You could do that, certainly; they might like to bip them around the floor and putt them underneath the oven. But it's actually an idiomatic phrase meaning "to throw pearls before swine", that is, giving a valuable thing to someone that doesn't value it.
Now I've got to wipe the floor again, it's raining cats and dogs out there.