Kobolds are known for having the ability to create dangerous unpredictable traps to protect their homes 

Gain proficiency with Tinker's Tools, double proficiency if already proficient, Add +1 to DEX or INT. You can spend ten minutes to set up a trap that deals damage based on components used. Traps have a dc equal to 8+INT+Proficiency, traps such as hunting traps and snares get a bonus to the save DC equal to your INT modifier. You can convert non-magical traps into components when disarming them, you gain resistance to trap damage and advantage on saving throws from your own traps.

Damage type is determined by component used, examples for traps that can be built are but not limited to;

• Spring and sword mounted near a door that triggers when it is opened, swinging the sword dealing damage based on the sword used.
• Grease filled bucket that knocks over when its pulled over by a small line of wire, filling a 10ft square with the effect of a grease spell.
• Box full of insects that opens when the trigger is activated, spawning a swarm of insects for 1d4 rounds.
• Crossbow pointed at a large bell that fires when a door is opened.