Poison Pin (Trap idea)
Here's one for you Dm's that want a trap that just keeps hurting. The players are walking into a room a one of them opens something. As they open it a clicking sound comes from cross the room. At this point the person who opened the thing that caused this sound will have to make a dex save & on fail will get hit by a tiny needle that will do 1 damage to the person that was hit. How ever, for each seven seconds after (1 turn) that person will take an addition 1 damage due to poison which was on the tip of needle. This will continue till they lose 25% of their Hp & or cure themselves of the poison.