Cats pooping outside litterbox only at night

I need help solving a litter box problem. I have 2 cats that prefer an extremely clean litter box. We have a litter robot bubble litter box unit that cleans automatically eight minutes after the cat uses the box. They did fine for the first month but then they started pooping right in front of the litter box, but only during the middle of the night. I've never caught the cats in action so I don't know which one is doing it. But they poop just fine in it other than when each night I wake up to a pile of poop. It's not there at midnight but is there by 8 am. I have a litter track mat in front of the litter box (put it there thinking they'd poop on it instead of my carpet), but they poop on my carpet right in front of the mat. I've cleaned with stain remover + enzyme cat urine cleaner. Any suggestions.

Thank You,

Roses

Have you tried adding a second litter box?That might be helpful if they just want an additional place to go.

This article has some additional suggestions that you may find helpful: http://www.thecatsite.com/a/how-to-solve-litterbox-problems-in-cats-the-ultimate-guide

Good luck sorting this out- I know it's quite frustrating!

Yes, I've tried adding a second litter box. It worked for a few nights and then poop on the floor in the morning again.

Hey there!

Was there anything that could have happened at night time that would have startled them while they were attempting to use the box? And is this fancy box a covered box?

Cats are prey animals - meaning, even though they hunt small creatures and seem ferocious, that they are actually 'the hunted' when it comes to living in the wild. Cats are the hardest to diagnose with some injuries and illnesses early on because they will hide it until symptoms finally start showing up at their worst point: because they don't want to seem weak to predators.

Sadly, this worried mentality can carry over to the simplest thing such as not feeling 'safe' around their litter box.

Many people have had to move litter boxes to different areas of the house because the box was in a laundry room where the dryer made a loud noise when they were inside and spooked them, or have had to remove the cover on the litter box altogether because one cat pounced on another cat while it was exiting the box and he didn't feel safe until he could 'see' it coming! 

So, my questions for you are: Where is the litter box located (i.e. a laundry room, the garage,etc.) - is it somewhere where at night a loud noise could have taken place and startled your kitties? Have you tried moving it's location and where is the 2nd box located? Could the cleaning mechanism in the box have scared one of them trying to use it at night? Is it possible that one cat is trying to play with the other cat while they are using the box and now that cat is afraid to enter it? If it IS covered have you removed the cover?

Ok, I'll stop with the survey! But let me know if any of that relates/works for you!