trap, snare
罠 centers on a device for catching something unawares: a trap or snare. The idea is always a hidden or deceptive mechanism that captures.
罠 combines 罒 (net) with 民 (people), suggesting a net for catching people or animals. The exact historical development is uncertain, but the component combination clearly points to a trapping device.
A net (罒) is set over the people (民) to catch them unaware — that's a trap.
For ビン, imagine a trap made from a big bin: the bin snaps shut like a snare. Bin -> ビン.