We’ve been using a glass with any kind of fruit paired with a funnel-shaped piece of paper with a small enough hole placed on top of the glass’ opening so that the flies can enter through the small opening but are usually too stupid to exit out of. What happens is that they all gather inside the glass, under the funnel, but can’t escape, so you can just release them all alive outside.
We’ve been using a glass with any kind of fruit paired with a funnel-shaped piece of paper with a small enough hole placed on top of the glass’ opening so that the flies can enter through the small opening but are usually too stupid to exit out of. What happens is that they all gather inside the glass, under the funnel, but can’t escape, so you can just release them all alive outside.
They’re disease-ridden vermin, you shouldn’t be letting any of them live.