The crack between the top and wall is minor, it's the horrific drywall joint below the casing that bothers me. Looks like nail pops already and no tape.

I doubt that that minor crack will exasperate the ant problem. It's not officially spring at my house until a pair of ducks start hanging out in my pool and its not officially summer until the ants come marching in to my kitchen.
Both the ducks and ants arriving have been happening like clockwork since we bought this house 12 years ago.
I do wonder though about the ants though because every year I use ant traps and the ants quickly disappear so I assume I have killed them all but the next year there they are again.
Good luck on getting rid of the ants.
I am sure you won't even think about that little space once your backsplash is installed.

Thank you both! Badgergirl, the ants are a whole other thread!

Trebruchet, I can ask them to fix the joint. I didn't think it was important since the tile was going over it and it was a short section. But I suppose, the drywall should be securely attached. I will check the rest of the wall too,. Thanks for pointing that out.

So should there be drywall below the crack, behind the cabinets? I am not entirely sure it is a crack vs. the dry wall just ends there

Thanks!

I think I read that you need drywall behind the cabinets for fire suppression purposes - it won't stop a fire but it would slow its spread. It doesn't have to be perfectly finished - tape and skim coat the seams.

I am concerned about that drywall joint as well. Drywall joints should never meet at the edge of a door or window, future settling issues will cause it to crack, even through tile. There should be a solid sheet of drywall with the window opening cut out of the center, if that makes sense.

The crack you are concerned about doesn't bother me, it reminds me of scribing the wall to get the stone to fit perfectly.

Thank you both! Texas, the house is about 15 years old. Do we think it has finished settling or is it still an issue. The window is new. Do I have to ask the contractor to redo it? Or will it be sufficient if he tapes it better? I am assuming it would be a fair amount of work and cost to redo it if at all possible since the upper cabinets have been installed as well. I think there's about 4" of wall between the window and the uppers. I'll measure the window when I have more tie.

Thank you

Thanks!

Right or wrong this is what I would do. If the repair person was willing and free, I would tell them to return and use sheetrock screws to secure the drywall, then sand the joint and apply a smooth coat of mud. You can lightly sand it smooth. That's under the window.
Regarding the so call "crack". I am not sure I would want them to touch that and mess it up more. You might talk to their supervisor and judge by his/her reaction.
If the crack really bothered me and I was afraid that person would mess it up worse I would talk to the tile person. I think you will find that the tile person will tell you that he/she has to deal with sloppy work like this all the time and it is not a big deal.
But if it really drove me crazy, right or wrong, I would carefully place masking tape on top and bottom edge of the "crack" just so the crack is exposed. Then I would run flexible caulk to fill in the hole and push it into the crack. DO NOT let it protrude out the crack, that would create a worse problem. You are just filling the hole. Keep it off the sheetrock and counter. You just want it to fill in the crack and not interfere with the tile work.
Regarding ants; they will get in your house a thousand other ways.

I just went back to look at the picture. I guess I imaged worse. It is not that bad. Certainly should be fixed in the tiling process. The tile mortar should fill it.

My house is 20 years old and is still settling. Part of it is because we have been having extreme drought conditions for the past few years. I had a crack develop above a window.

No matter how much tape is put on, it is still a weak spot. If it were me I would want it done right so there isn't future cracking issues there.

The weakest spots in drywall are seams and around doors and windows, you should never combine the two.

If it were just going to be painted I would say not that big of a deal, when it eventually cracks, you sand the area, tape, mud and float it, spray some new texture and paint it and its good.

My concern is that tile will be over it and when it cracks, it will crack the tile as well.