VFT's are designed to *not* eat very small insects..
Originally Posted by wcrimi
the trap fully closing actually occurs in 2 parts:
1. an insect (doesnt matter what size) brushes against the trigger hairs, triggering the trap.
that alone isnt enough to "finish" the closing process and begin digestion..
Notice at this first stage, there are still gaps in the trap..its not yet fully closed, its not "sealed tight"..the "teeth" are only intertwined loosely..
2. if the bug is large enough to *not* escape, further movement by the bug stimulates the trigger hairs further, which "tells" the trap it has a good live bug, and "stage 2" can commence..the teeth will bend outwards slightly, the two halves seal their edges together, the trap fills with fluid, the bug drowns in the fluid, and digestion begins.
If the bug is really small, like a gnat, it can easily escape out of the loose "cage" after stage one..this is deliberate, because it isnt worth the plants effort to digest something so small..
also inanimate objects: rain, dirt, etc, that might accidently trigger a trap to close, wont continue to move, and so the trap will quickly re-open and wont waste any effort trying to digest a non-bug..
Whether you believe evolution, "nature" or God created the VFT, its really an amazing system..