its about managing risk-everyone is aware that you can't keep birds in completely sterile conditions but one sparrow getting into your run is preferable to flocks of starlings eating the corn you've just thrown out for your hens.
my geese are in a covered run outside, they've settled well now and are eating well etc.
I'd have thought that on a smallholding forum, people would be well versed in basic biosecurity tbh and this is all this is at the moment. that's not a dig, I am just surprised.