It's tricky because they keep opening new lanesHow do you block a sparrow superhighway?
I block a lane, they open another! I can't see the new lane until it's been used so much it's got streetlights, an on ramp, an exit and speed cameras Seriously, I wouldn't bother keeping them out but every time I go in, they panic and fly into things as they try to escape. There's also the food hygiene risk to consider.

