Here are some great ideas. As well as having as large of a cage as possible and changing out the houses frequently...
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And here is my list for bordom busters some are well known and obvious and some are from personal invention...
Guinea pig toys:
1. A box: Really, any kind of box will do. An empty soda box, tissue box etc… Cut an entrance hole big enough for your guinea pig to fit through, make sure all plastic tape or laminated coating is removed, and place it in their cage. Don't be surprised if it has chew marks on it within the hour. Remove when soiled.
2. Cardboard rolls: Take an empty toilet paper or paper towel roll and cut it length- wise so there's no chance your pig will get stuck in it. You can give this to your pig as is or stuff it with hay. Or take a paper punch and punch a hole in it and string it up in the cage. They like to push it, pull it and try to get it down. Another one is a snack tube. Take a toilet paper tube and make 2 slits in each end so you can fold them in to make a container for their favorite fruit or veggie treat.
3. Paper plates: Some pigs enjoy flipping these around; others like to hide under them. I take a paper plate and fold it in half so it makes a kind of tent. Make sure you use a plain paper plate and not one with any kind of plastic coating, as plastic and laminating are very harmful to guinea pigs' digestive systems.
4. Tissue paper/newspaper: take plain white tissue paper, crumple it a bit and place in her cage. I think she enjoys the sound it makes when she moves it around- plus, it doubles as a hiding space. Open a sheet of news paper and stick it in the cage. Also very simple, but a big hit. Good to chew on, crawl under, play tug-of-war with. Make sure there are no staples. Most newspaper is made with soy-based dyes which are safe for the pigs. Check with your newspaper company if you are not sure.
5. Stuffies: Take a sock, stuff it with either clean bedding or hay, and tie off the end (you can also sew it shut if you like). Some pigs like to shove their socks around and show them whose boss while others cuddle with them almost like a stuffed animal. Plus, if it gets dirty you can wash it or just throw it away. Stuffed animals with NO beans inside or button/hard noses or eyes. They like to cuddle with them, bury under them, push them etc…Make sure they don’t chew it enough to get to the stuffing. They could really get sick. If they keep chewing to get to the stuffing remove all the stuffing and restful with hay and sew it up!!!
6. Pig sized sleeping bag: This sounds complicated, but really isn't. I used two old washcloths, but any similar sized pieces of fabric will do. Take the fabric and sew them together on three sides, then fold the open side back a bit (like a turtleneck sweater) so the sleeping bag stays opens. Voila! You have a pig sized sleeping bag they'll love to sleep in.
7. Tent: Take a piece of yarn or twine and tie it to the corner or in the middle(across) your cage, then place a piece of fabric or a sheet of newspaper and fold it over (I used part of an old pillow case). It sounds too easy to be useful, but my guinea pig loves to sleep in this tent and keep one eye on me to see if I approach the kitchen. There are also little pre-made tents available at pet stores that sell ferret toys but all you have to do to make one is attach various panels of fabric to the corner of the cage. Try different sizes and shapes to make creative enclosures
8. : House: a colander that was the same size as a plastic pigloo, plastic igloo shaped home for guinea pigs, cut a hole in it as big as your pig and you have a house. You can use wood and make your own. You can take Lincoln logs and make a little house. Be creative. Guinea pigs can see color and have color preferences so have fun changing it up!!!
9. Paper bags: either stuffed with hay, veggies, other edibles or empty.
10. Tunnels: there are many options, bending a grid into a curve and covering it with a towel, a piece of fleece or even a cheap book cover. Any box, container can be made into a tunnel. Oatmeal containers, 4 or 6”PVC piping. I especially favor 6” PVC piping. I cut an 8 inch chunk out and then cut an inch off the bottom creating a C shape so the tube doesn’t roll and so it is more comfortable to lay in.
11. Bricks, Cinder Blocks, Rough Stones or Ceramic tiles: May help in wearing down nails. Make a pad of bricks available in the summer time. They can lie on the cooler bricks. Also, you can put the bricks under the water bottle to help absorb drips and ensure they get their little claws on them. Or, make a little low pyramid with bricks (assuming you have a large cage) and put the food on the top platform. With bricks, cinder blocks, and stones, make sure there is NO danger of any item falling or dislodging in such a way that could hurt a piggy or piggy paw. Try putting the stones or bricks under or next to the hay racks, especially if you hang the hay racks from an upper deck in a cube cage. A cinder block with holes in it can make an interesting gym for them.
12. Balls: ping pong balls/Tennis Balls: better than cat toys as they will roll around easier on bedding.
13. Tossies: any lightweight container they can flip, toss or push. Like cleaned butter or margarine tubs place a favorite treat under and see how long it take to flip it.
14. Pine Cones: don't have the pine bedding risk, but they should be sterilized first. Bake first to sterilize at approximately 200° for 20-30 minutes on foil to catch any sap drippings. These might be a favorite.
15. Reflective objects: Mirrors are great for any animal. Make sure they are pet safe if you are putting it in the cage.
16. Fruit Tree Branches: Good chew treat, free if they come from your UNSPRAYED backyard. Untreated wood, twigs and logs that have been aged for at least 3 months. Apple tree branches can be eaten fresh off the tree. Stay away from: cherry, peach, apricot, plum (fruit trees with pits) and redwood branches, which are all poisonous.
17. Wooden Blocks: For chewing and pushing around. Please make sure any children's blocks are not coated with any sealants (shiny or smooth looking) and are basically just plain wood.
18. Snuggle tunnel: all you need is an open ended container (box, oatmeal container etc…that has 2 holes large enough for your guinea pig) and a piece of fabric 2-3 times longer than the container (preferably fleece). You roll up the fleece like a taco. Then insert it through the opening of the container. Center the container in the middle of the fabric taco. Then take the fabric at one end and start to unroll and flip it over the container. (similar to flipping up a cuff of a sleeve). You can also check out the you tube video I made there is a link in my website.
19. Look out: Take a sturdy box, stool or house that has a flat large roof. Add a ramp and place it in the middle of the cage. You will have given them a great look out spot to run up to and run down from.
20. Food balls: Take a piece of newspaper or other kind of safe paper and put a days worth of pellets in it. Pull all edges of paper up and twist real tight like a candy wrapper. There is no tape, glue or sting needed. You can put it in the cage as is or you can punch a few holes in it to make it a bit easier to open depending on how much your guinea pig likes to chew. You can also do this with any timothy cubes or fruit or veggie treats.
21. Food bounce back. Take a large or extra large plastic Easter egg and fill the bottom (fatter part) with cement, or take rocks and white glue to make a sturdy base. Then take the top half and very carefully carve out holes large enough for food to fall out when knocked. When all done you can fill with food and set in cage. They can knock it around and food will spill out.
22. Watermelon (or other food) House. Make sticks and lay them in down log cabin style to make a little box. Or you can take half a watermelon rind and cut a door in it for them to eat from.
23. Mini bags. Sew up a small bag with rice or barley. In the winter or if you have an older guinea pig just pop the bag in the microwave for a few seconds and let the piggies cuddle up to it. (caution once it is wet it will make the rice and stuff yucky either put the rice in a plastic bag first or put it in a plastic bag and cover with a piece of fleece)
24. Pellet ball: take a hollow hard plastic ball and drill a few holes that are a bit bigger than a pellet. Drill about 3-5 holes into the ball. Then stuff the ball full of pellets and let them nose the pellets out. They will chase that thing until it is empty. A good way to keep piggies entertained.
25. Foraging pot: Take a large heavy container like a glass 8x11 baking dish. Put in some pellets, some hay, some tiny pieces of veggies. Then top with bits of cardboard, some paper, those wood chews you always buy but they never touch etc… Put it in the cage. The piggies will have to dig for their favorite treats and it will keep them busy and entertained for a long time.