That is what the purpose of the clips is. To keep the lid on, even if it is "owner proof". It's either snake-proof or it's not. I use metal c-clamps to hold the lid of my iris tub on, and yes, it's a pain to get them off and put them back on everytime I want to get her out, but it's MUCH better than her being lost in my house. Is your lid one of the sliding kinds? Even if you think it fits tight, snakes are VERY flexible, and even if you think it's snake proof, it's usually not. I would just rather be safe and, although it is a pain to get those clips on, that is a good sign. That means that snake ain't coming out!