I am behind on my photos as this posting illustrates. Laura and I encounter this carnivorous plant on our evening walks along Sandy Cove Road, Halifax.
The petals, clam shell like, remain open until activated by the sticky nodules on the end of the tentacles. Once activated by an insect the clam shells close and the meal begins.
Sundew produces a small white flower in late summer that extends far beyond the plant, perhaps a form of protection for the nectar transferring insects. You don't want to trap the good guys!
Notice in the photos that some of the traps are closed.
Lots of details on this family of plants can be found here: https://en.wikipedia.org/wiki/Drosera