How do you cat proof your home?  

to me the only way to make your home safe fotr cats is to treat your home as if you had a toddler in the house and carry out all the same precautions. The only difference is that this toddler can jump lol
blessed be

I never felt the need to cat-proof..except by making sure the door to the basement was always closed. My cat doesn't like to scratch all that much. He prefers sleepy by the window and playing...I guess to him, I'm the scratshboard. However, if you want to reduce damage, just let your cats go outside. They'll come back too worn out to destroy things.

We put child locks on all the lower cupboards because some of our cats like to open them and sleep inside. Whether they sleep on our dishes (and get hair all over them :) ) or they crawl over breakable things and knock them over. Thankfully they don't break often.

But since we've done that one of our cats has started opening the higher cupboards in our kitchen bu climbing on the counters and reaching up! What a pain! =P lol

We've had to put things away. Most of my tables and shelves are bare now that we have cats. They have even gotten into the toaster oven. I have to be sure it's unplugged except for when I use it. And, do like the other people suggested, put toddler locks on doors you don't want them in. Also, they need something to play on and scratch. So, you might purchase something along those lines. Pet stores and even someplace like Wal Mart all have cat trees and scratch posts. If they have something else to play with, they might not want to get into the cabinets and closets.

You can get those plastic child locks for the cabinets. I do NOT put any type of poison down in my house for any reason. If the ants eat the poison then your cat eats the ants, your cat can die by ingesting the poisoned ants. Same thing with any other poison--animal eats poisoned item, animal gets sick, possibly dies.

Wipe your counters with bleach and let it air dry. The ants will be gone. Spray bleach water in places where they are (behind the stove, behind the fridge or under the dishwasher).

As far as the closet goes, I keep something heavy in front of it otherwise they climb my clothes to get to the top shelf in the closet to sleep.

I don't think you can cat-proof your house. They'll just do whatever they feel like doing. At least my cat does.
But don't worry, they're not stupid as others pets may be, it's almost impossible to poison a cat, let alone the cat poisoning himself.
About the closet... my cat gets in mine every morning, and just sleeps on my sweaters. Never touched one, thank god.

How many cats do you own?