I like this kind of cat box because cats usually don't get litter everywhere and cat can do there business in private!

Pros: give cats some privacy

Cons: some cats don't like it

These are the best thing. My cats scratch the sides when they are done. Without the lid they threw litter everywhere. It also looks better and cuts down on odors. Would never go back to ones w/o lids!

Pros: I love these

Cons: none

My cats all prefer litter boxes with lids, though I did have to leave lid off for awhile after adopting my 3rd cat. One of the first two seemed to feel trapped when he went into litter box with lid during that time -- what if that new cat came to the door while was in there? After giving them some time to adjust to the new arrival, I put the lid back on and they are doing fine. They appear to like the privacy the lid gives them.

Pros: durable, gives cat privacy

Cons: none

My girlfriend has one of these for her cat, and it works very well. It's nicer looking than an open litter box, too.

Pros: Nice looking

Cons: None

Great litter box, Big so it helps alot. Still neds to be cleaned at least once a day though.

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[updated on 2008-01-31 10:50:41]:
Easy to clean, Great for a very messy shelter. They usually have two or more in each room. Very effective!!!

Pros: Traps in stink

Cons: none