Thanks for your comments and interest. I'm glad to see at least one other has observed the same thing as me. I've been considering running a little experiment to go someway to proving the observation using cotton buds, some glass jars, some old chrysalis maggots from the fishing bate shop , sugar water and of course Dionaea nectar. Some jars would have only sugar water on the cotton buds, others with harvested Dionaea nectar. Once the chrysalis hatch into flies I could observe the behavior in a more scientific setting.