Yes they self fertilze. Wait till the seed head turns brown and is dry. Then just break it open and sprinkle onto some moist media on a sunny windowsill.

I just let mine drop seeds in my VFT pot when ready. Without any assistance from me my original 3 plants have managed to seed and sprout 20-30 plants.

i have them in a huge terrarium. do i have to collect the pods or just let them drop.

You could do either. It depends upon how much control over the situation you want. Wait until they are black and looking like they are about to burst before dealing with the pods, if you go that route.