My guys absolutely LOVE IT when I make them "Foraging Boxes" and put them inside of their cages before I leave in the morning. They keep them totally occupied and mentally stimulated for hours and hours, and they don't even notice I'm gone or that they are inside of their cages. And they're cheap and easy to make!!!
All you do is find the largest cardboard box that will fit inside and on the bottom of your bird's cage comfortably, and then gather as much paper/newspaper as you can (I just go to the convenience store and grab a ton of the "free" newspapers, like the Bargain Sheet/Ad Bargain/Auto Trader ones that they don't care if you take a ton of for free). Then you crumple the paper/newspaper into balls to fill-up the box. i also usually shred some paper and put the pieces throughout the crumpled-up paper...And while you're filling the box up with the paper, you want to be hiding a bunch of his favorite treats throughout the box, in-between the crumpled paper, inside of some of the crumpled-up balls of paper, at the bottom of the box, etc. I always place a few treats right on top of the paper in the box so that they can see that they are there, and that gets them interested and they start digging. Make sure you stick a few right below the top so they can see that there are treats inside the box as well. My guys spend hours and hours ripping the newspaper apart, finding the treats, and then my Senegal and my Quaker both start on the cardboard box itself once they think they have found all the treats in the box, though they always leave some behind and then go back and do it all over again...Depending on which bird it is I use different nuts either in the shell or already shelled (my Senegal can crack Almonds, Brazil Nuts, Filberts, Walnuts, etc., but the smaller guys can't, so I just use the already shelled nuts), whole sunflower seeds in the shell, pieces of dried pasta, pieces of dehydrated/dried fruit work really well, DRIED CHILI's!!! They all love them! Pieces of cereal that they like that aren't sugary, like plain Shredded Wheat, plain Cheerios, plain Bran Flakes, regular Granola, Pumpkin Seeds, etc. They spend their days just ripping and tearing and finding all kinds of different goodies!