i'm totally new at CP also. from what i have read, they don't really need to be fed, however, feeding them will make they grow better. i have one ceph and one sundew. ceph is doing amazing. but my sundew is just struggling along. nothing indciating that it's dead or dying, but it's not doing too well. just limp and what not.
per what i have read, some sundew will curl the leave in few hours once it has caught the prey and you will be able to see it working. but not sure. i don't have gnat or anyting flying in my study to feed them, i'm hoping with weather improving in next few days, i might find an ant or something that i can drop on it and my ceph's big pitcher.