Mustang, I'm no expert on dogs, but from what I've read, dogs don't have feelings of anger. He may simply be bored and trying to find something to do. I can't say why it started all of a sudden.

Also, you must scold a dog in the act or he won't understand why you are angry with him. He has no clue why you are mad and put him in his kennel and is not teaching him anything.

Daisy gets in plenty of trouble, but I don't scold her, unless I catch her, or if I do, it's a momentary thing and lasts long enough for me to let off some steam. Now I get more angry at myself for forgetting to close the closet door, or leaving food on the counter, or not shutting the laundry room door where the trash is. The problem is, Daisy is smarter than me and I eventually forget to cover all the bases, but she NEVER miss an opportunity when it comes to food.