In a large mixing bowl, combine the ground bison with crushed ice. The ice helps keep the mixture cold and binds the meat together.
Add garlic, fennel seeds, smoked paprika, salt, black pepper, and red pepper flakes to the mixture. Mix thoroughly until all ingredients are well incorporated.
If using sausage casings, soak them in warm water for 30 minutes.
Stuff the sausage mixture into the casings, being careful not to overfill. Twist the sausages into your desired length.
Tie the ends of the sausages with butcher’s twine, and chill them in the refrigerator for 30 minutes before cooking.
Heat a skillet or grill to medium-high heat. Cook the sausages for 8-10 minutes, turning occasionally until browned and cooked through.
Serve the sausages as desired – on buns, with roasted vegetables, or as a breakfast dish!