If the traps are turning black b4 they open up, it means one of many things
1) too hot. The soil temp is above the reasonable limit. The plant cannot take extreme heat, the roots will fry, then in about a week, you will see something is not right.
2) Dormancy. If the temps are cool, and the light low, the plant might be trying to go to sleep.
3) Mold damage. Is there mold on the soil? It might be damaging the plants.
4) watering from the top. It is best to water from the bottom. This helps prvent rotting of the plant.
5) bad water. Distilled, Rain or Reverse Osmosis Water ONLY. NEVER Tap, drinking, mineral, bottle
6) Soil. The plant needs to be in either:
50% peat moss 50% perlite
50% peat moss, 25% silica sand, 25% perlite
50% peat moss, 50% silica sand
50% long fiber moss, 25% silica sand, 25% perlite
NEVER plant it in Top soil, or regular dirt.
7) overfeeding. The plant should only eat a few bugs a month tops. If overfed ( or fed past midnight ), the plant can stop producing new traps.
8) fertilizer NEVER fertilize the plant. That will burn the roots.
Hope this all helps