Mirrors
Bird Toys
Chew Blocks
Blocks of wood
Wooden House
Cat Ball with Bell
Another Guinea Pig
Toilet Paper Rolls
Index Card Folded in Half
Ball hanging from String
Most any Cat Toys
Cardboard Box
Peice of Untreated Paper
Mirror with a Bell
A Blanket (when out of cage)
Cardboard Tube to Hide In
Can (make sure no sharp edges)
Shoebox with Holes