Securing a Sterilite tub

[Lolo76]

That said it's still not a bad idea to cover your bases, especially if the snake can get lost in the house

Exactly... even though it's doubtful they'd escape a locking tub, better safe than sorry!

And to the OP, I just put one large binder clip on either side of the lid - seems to work fine. Most of my snakes are in a rack now, so that's no longer necessary, but I still do it for the separate (corn snake & QT) tubs.