Mental stimulation is as important as physical exercise for dogs. But enrichment toys from pet stores cost $15-30 each. These DIY versions cost pennies and provide hours of mental exercise.

The Muffin Tin Puzzle (Easy)

You need: Muffin tin, tennis balls, treats

How: Place treats in some muffin cups. Cover all cups with tennis balls. Dog must move balls to find treats.

Cost: Free

The Snuffle Mat (Easy-Moderate)

You need: Rubber sink mat with holes, fleece fabric strips

How: Cut fleece into strips. Thread through mat holes and tie knots. Scatter kibble in the fleece for your dog to sniff out.

Cost: $3-5

The Frozen Kong Alternative (Moderate-Hard)

You need: Plastic cups or silicone molds, wet dog food, treats

How: Layer wet food and treats in cups. Freeze overnight. Pop out frozen block and give to dog.

Cost: Under $1 per treat

The Towel Burrito (Moderate)

You need: Hand towel, treats or kibble

How: Lay towel flat. Scatter treats. Roll towel tightly. Dog must unroll to find treats.

Cost: Free

The Braided Tug Toy (Play Toy)

You need: Old t-shirts or fleece

How: Cut fabric into 3-inch wide strips. Group into 3 strips. Braid tightly. Knot ends securely.

Cost: Free

Mental exercise tires dogs more than physical exercise. A 20-minute puzzle session equals an hour of walking for brain fatigue!