The Big Brother/Sister Trap

So here's the deal. I'm the youngest of three siblings, and my big brother and sister have always been super cool with me. We play video games, watch movies together, share snacks, all the good stuff. But there's this one thing that gets under their skin and drives them nuts. It all started when I was about 10 years old. My mom would buy these giant boxes of cereal like Froot Loops or Lucky Charms, which have those crunchy, sugary pieces that are perfect for snacking on throughout the day. The box comes with the big flakes and a bag full of the smaller, crunchier bits at the bottom. I noticed early on that I could eat all these crunchy cereal bits as snacks without my siblings noticing. One day, they were both getting annoyed by me because there weren't enough of those crunchy bits left in their bowls for them to enjoy properly with their milk. It escalated from there into a full-on battle over who gets the last bits. Nowadays, whenever I hear them rummaging around in the kitchen late at night or early morning, it's usually me hiding somewhere eating up all the delicious, crunchy cereal pieces before they can get to them. They've tried putting locks on the cabinets and threatening to buy only non-crunchy cereals but nothing works because there’s always a way. But here's where I really feel like an asshole: my sister starts her college semester soon, and she wants to leave home with as much of that cereal goodness for herself as possible. She told me straight up to stay away from it while she’s gone but there's no guarantee I won’t sneak into the kitchen when she isn't around. So am I really this annoying? Should I stop hiding snacks and just be upfront about my cereal hoarding habit? Or is it okay for siblings to have a bit of harmless sibling rivalry over stuff like this?