Well it certainly looks like a Drosera of some kind - there are lots of different varieties. Its certainly a fly trap.

Looks like Galinsoga quadriradiata to me. It's a weed.

Goodness Landgirl, where on earth did you learn that one?
Can't argue with quadriradiata, its well named. Do you know where it comes from, I don't think that variety is a British native. Ignore me Teaman, and take it back!

All the ones I've seen have yellow central petals though and don't have the 5 'sepal' structures from behind the flower.
Not sure why quad as the aprts don't appear to be in 4's.

If it is, originally its a native of Mexico and its an annual.

There are two species, G. quadriradiata and G. parviflora. They are quite difficult to tell apart, but the former is normally quite hairy. Its common name is Shaggy Soldier! They both come from S. America and are common urban weeds. No idea where the quadriradiata specific name comes from!

Looks like one of the many varieties of Drosera, aka. sundew plant, to me. This too is a carnivorous plant. Take a close look at the hairs on the leaf to see if you can find a tiny drop of sticky fluid on the tips of the hairs. If so then that's it. The insect gets stuck and the leaf will curl up around it as opposed to the open clam shell like leaf of the Venus fly trap snapping shut when the trigger hairs are touched.

I thought that at first too but when I looked up the Galinsoga I could see what Landgirl means. I assumed at first that the quadriradiata was referring to the four very hairy long thin sepals, but looking again I see there are five...I'm going back into my hole.

Suggest an experiment. Why not volunteer any small insect, place it on top of the hairs on the leaf, if it sticks to the leaf and the leaf curls up around it, you will know for sure.....unlike the fly trap, Drosera does this process slowly.