Damage done during a sleepover.

[oopsie]

I'm not sure if this is evidence or not but one of the other things I found (which is REALLY odd) was the dog or cat vomit that I found on my floor near the scribbles on the edge of the countertop had some of my liquid hand soap in/on it! I'm looking at it like "seriously??!" The dispenser was in its usual spot beside my kitchen sink.

Even as far as pranks would go, this just make zero sense to me...unless of course someone thought it would be funny to feed liquid hand soap to one of my animals which then caused them to vomit...? 

That part doesn't say "prank" to me, it says "pet horked and then kid misguidedly tried to clean it up," and by "clean" I mean "dump some soap on it and hope someone else takes care of it."

LOL!! That's pretty much exactly what my mom said too.

[CakeBeret]

Sometimes kids can be irrational about 'fessing up.

Once, when I was about 9, I was at a family friend's home. I washed my hands in the kitchen and dried them on a towel. A few minutes later, the mom was very upset that the towel was wet, because apparently it was an heirloom and not supposed to be used. I was shocked, and I was painfully shy at that point in my life, so I refused to confess. The mom made all of us kids sit on the couch for two hours waiting for someone to confess, and I couldn't bring myself to do it.

OP, I think mentioning it to the kids' parents is the best thing to do. It would drive me crazy not knowing, though! 

[jibby]

...
I wouldn't rule out the girls,  honestly.  Teen girls can be bad, too.  There was a post on here last year where the OP's daughters swore up and down they had nothing to do with their uncle's house being broken into, but later it turned out they DID give friend's access to the house while their uncle was away.  As a former teenage girl, I can admit we often do stupid things and deny them, and I think we get away with it more because we lie well and I think people are predisposed to think boys do more damage than girls, and I doubt that is the case.  I like the PP's suggestions of not laying blame anywhere, just telling the facts and stating no sleepovers as a punishment for everyone.
...

I agree that it's hard to really rule out anyone; that thread popped in my head as well.  I want to say it was BalletMom.  Her daughter's deception completely tore apart their family, and the daughter wasn't even made to offer a sincere apology or effort to make it right.  It was one of the most disturbing threads I've read. 

OP said she had reason to think it was the nephew, so perhaps the threat of no more sleepovers (without actually accusing anyone) will encourage a confession.

[DollyPond]

Maybe they had a late night game of Truth or Dare and no one wants to admit it.

[lisastitch]

POD to JenJay.
I would talk seriously to each child individually (though you might ask their parents talk to your nieces and nephew) about what happened, how much it bothers you, how much you want to resolve it, and that it means it's hard for you to trust the children. 
Our children grew up knowing that if they did something wrong and confessed they would receive an appropriate punishment, but that if they lied about it, they received the appropriate punishment for the original infraction, plus punishment for lying about it. 
One of the things we really emphasized was that when they lied about something, we couldn't trust them, and we demonstrated what that meant ("No, I'm sorry, but you can't stay home alone while I go to the store because I can't trust you right now.").  Then they had to earn our trust again. 
Of course, if one of them was sleepwalking, they won't be able to "come clean", but I assume that you'll be alert for other possible sleepwalking episodes.

[Lynn2000]

I wonder if, when the answer is finally known, it will all make sense in some kind of bizarre way.

Like, kid gets up for a midnight snack of pistachios. Dog grabs the bag and starts eating them on the couch, making a mess. Kid tries to lure dog away with dog food. Dog won't fall for it, so kid tries to sweeten the pot by putting the dog food in the cheesecake. Eventually dog throws up, kid tries to "clean" it with the soap--maybe thinking the soap would dissolve it somehow? I've got nothing on the permanent marker on the counter, though, unless someone thought they could "color over" the mess?

I'm assuming there's no way it could be solely the work of the pets, right? If it weren't for the permanent marker scribblings...

[Yvaine]

I wonder if, when the answer is finally known, it will all make sense in some kind of bizarre way.

Like, kid gets up for a midnight snack of pistachios. Dog grabs the bag and starts eating them on the couch, making a mess. Kid tries to lure dog away with dog food. Dog won't fall for it, so kid tries to sweeten the pot by putting the dog food in the cheesecake. Eventually dog throws up, kid tries to "clean" it with the soap--maybe thinking the soap would dissolve it somehow? I've got nothing on the permanent marker on the counter, though, unless someone thought they could "color over" the mess?

I'm assuming there's no way it could be solely the work of the pets, right? If it weren't for the permanent marker scribblings...

  I like this idea--that it all makes a unified story in some way!

[oopsie]

I wonder if, when the answer is finally known, it will all make sense in some kind of bizarre way.

Like, kid gets up for a midnight snack of pistachios. Dog grabs the bag and starts eating them on the couch, making a mess. Kid tries to lure dog away with dog food. Dog won't fall for it, so kid tries to sweeten the pot by putting the dog food in the cheesecake. Eventually dog throws up, kid tries to "clean" it with the soap--maybe thinking the soap would dissolve it somehow? I've got nothing on the permanent marker on the counter, though, unless someone thought they could "color over" the mess?

I'm assuming there's no way it could be solely the work of the pets, right? If it weren't for the permanent marker scribblings...

Yeah, like the ending to a bizarre episode of CSI. I'm going to talk to each of my kids again, one-on-one, and see if I can get any more clues or an idea to timeframe. One thing I do know is that the marker and vomit thing was done BEFORE I went to bed. I came upstairs after finishing watching movies with the girls at 1:30am and found them at that time. The other things could have been done then but I never thought to check (living room light was out so I couldn't have seen in there anyway). I checked in on both boys before I went to bed as well and both were in their beds, fast asleep.

Edited to correct spelling.

[White Lotus]

OP has at least one dog, so not a stranger, and no visitors, or the dog would have gone off, I think, waking OP.
The damage itself leads me to suspect age 11 thinking it is funny, or trying to prank the 6 year old who is scared of poltergeists by creating one, maybe after scary bedtime stories when they were alone.  However, the plot seems a little complex for one 11 year old acting alone.  What if the teens decided to prank the youngest with a faux poltergeist, and, clever little devils, decided to make the damage of a kind that points to the 11 year old?  A sister could come up with that, and her cousins would egg her on and join in the fun.   They are all good suspects, so I think handling it the way you did -- notifying the parents, not assigning blame, and imposing equal consequences -- was both correct and courteous.  Especially since there are other, less likely but possible, causes, like sleepwalking or even mental illness, the parents might want to look out for.

[RingTailedLemur]

The trouble is, the more time elapses the harder it gets for the kid to confess if he/she wants to.

I'm fascinated, OP, as it is a bizarre catalogue of incidents.  I hope you find out who did it - and perhaps more importantly, why.

[MrsJWine]

I woke up once rearranging the furniture in my room. I was bent over my nightstand when I opened my eyes, fumbled for the light switch forever and found several things in my room moved around. My brother walked out to our car in the middle of South Dakota winter in nothing but his underwear and lay down to go to sleep (he likely would have died if my dad hadn't woken up when he went out the door). A friend of my sister's who had quit smoking a while ago drove to the store in her bathrobe and only her bathrobe, bought a pack of cigarettes, smoked one, and went back to bed.

So I wouldn't rule out sleepwalking, especially since it's much more common in kids. It can also come and go. I would go months without sleepwalking and then do something really bizarre. I still do it about once a year. But it seems really, really weird that all of these separate things would have happened during one sleepwalking episode, unless there were some logical progression (logical within the dream) in the person's dream.

[athersgeo]

But it seems really, really weird that all of these separate things would have happened during one sleepwalking episode, unless there were some Illogical progression in the person's dream.

Fixed that statement; any dream that features pistachios, dog food and permanent marker does not strike me as having anything approaching logical progression! (This from the woman who regularly finds herself dreaming that the penguin who lives on her PC tower is giving her employment advice - though as far as I'm aware I've never actually left my my bed to hold the conversation.)

Getting back on topic, the other thing that occurred to me was that possibly there was no one single culprit. That perhaps the teens had done the pistachios and soap-in-puke while the younger/s did the marker and the dog food-in-cheesecake.

That might explain why no one was owning up - because no ONE person did it.

[MrsJWine]

But it seems really, really weird that all of these separate things would have happened during one sleepwalking episode, unless there were some Illogical progression in the person's dream.

Fixed that statement; any dream that features pistachios, dog food and permanent marker does not strike me as having anything approaching logical progression! (This from the woman who regularly finds herself dreaming that the penguin who lives on her PC tower is giving her employment advice - though as far as I'm aware I've never actually left my my bed to hold the conversation.)

Hah! I meant logical within the dream, which, as you said, is no sort of logical at all to people who are awake and sane.

[bonyk]

Maybe the perp put dog food on the cheesecake to get the dog to eat it, and the dog ate it and threw up?  And then the child tried to clean it?  No marker explanation.

Kids (even teens) do weird stuff that they know they should not.  I can think of a few things I did that I've since confessed to my parents as an adult.  They were mostly happy to have the mysteries solved.   

[RingTailedLemur]

...
I wouldn't rule out the girls,  honestly.  Teen girls can be bad, too.  There was a post on here last year where the OP's daughters swore up and down they had nothing to do with their uncle's house being broken into, but later it turned out they DID give friend's access to the house while their uncle was away.  As a former teenage girl, I can admit we often do stupid things and deny them, and I think we get away with it more because we lie well and I think people are predisposed to think boys do more damage than girls, and I doubt that is the case.  I like the PP's suggestions of not laying blame anywhere, just telling the facts and stating no sleepovers as a punishment for everyone.
...

I agree that it's hard to really rule out anyone; that thread popped in my head as well.  I want to say it was BalletMom.  Her daughter's deception completely tore apart their family, and the daughter wasn't even made to offer a sincere apology or effort to make it right.  It was one of the most disturbing threads I've read. 

OP said she had reason to think it was the nephew, so perhaps the threat of no more sleepovers (without actually accusing anyone) will encourage a confession.

Really?  Wow.  I remember the original thread (I just looked at it again) but I didn't recall that the DD admitted she had done it, after all.  Wow.