- Wed Apr 25, 2012 9:51 pm
The trap actually needs to be triggered twice, if I understand correctly; once to close, and once a little while later, to "check" that there is actually something in the trap.
This second trigger mechanism prevents the trap from committing the energy to seal and digest the insect if there isn't one... it stays partially open for a while in order to let an insect out that is small enough to fit through the hairs along the edge of the trap- these insects aren't worth the energy cost of digestion. Or, alternatively, the trap could have been triggered by a drop of water or an insect too large to get a seal on, giving that large insect a chance to escape since it won't be able to digest it properly anyway.
Anyway, maybe too much detail, but there ya go- if it wasn't able to put up a struggle, I would gently place a finger to either side of the trap a few minutes later and agitate it a little, to encourage the trap to seal around the insect. I do this a few times, intermittently every few minutes, just to be sure, because I'm not sure when that second trigger is necessary.