My fly trap caught a bug all on its own yesterday (I'm a newbie to carns, so bear with me.)

The trap didn't totally engulf the prey- it's head and a leg is out. My understanding is that these plsnts seal up and release digestive juices- does it need to completely seal up in order to do so?

I guess I'm asking if it will actually eat the bug if it's sticking out from the trap a bit.