Overview: An easily craftable mine that only makes noise when set off. Can be disassembled.
Description - This suggestion is mainly for when you want to hold a position by yourself and not get snuck up on, or be alerted to someone else's presence nearby. The idea is that you can craft a mine with common materials that when set off makes a very distinct "crunch" sound, alerting you that someone/something is close. The mine can be disassembled without any tools (although doing it without gloves risks getting a cut), meaning that other players who are cautious enough to spot it can remove it without you knowing.
Recipe: 3 short sticks + 15% duct tape = Stick mine
Inventory space: 4 cells. Can be disassembled although you only get the sticks back.
Action: Makes noise when set off. Nothing else.
Bonus - the Stick Mine can be upgraded to Upgraded Stick Mine. Recipe: Stick Mine + 12% duct tape. The only difference being that to disassemble an Upgraded Stick Mine requires you to have a knife equipped.