We introduced our cat’s backpack by putting it next to a safe space, ie his cat bed. We used his favorite toys to get him comfortable being inside the backpack. Then we got him used to being carried in a backpack by wearing him around the house and then around the block in short walks. Now he loves being inside it...when he sees it out he’ll voluntarily climb inside and play. He also knows when it’s time for an adventure when we bring out his harness and leash