I had friends (American) who lived in the Netherlands for a while. Their rental home included landscaping. What that actually meant is "sheep delivery". Periodically, a truck would come by and offload sheep into the large yard. Some days later, the truck would pick up the sheep, leaving behind a nicely trimmed (and I suspect well-fertilized!) lawn. We happened to visit when the sheep were working, and it was charming.
And to Rothwem's questions, I don't recall the size of the yard, but I'd guess there were maybe 6-8 sheep. Not sure how long they staye,d but I want to say it was a couple of weeks-ish.
As for what they left behind--it was basically just a "mowed" lawn. Short grass. This was sheep, not goats.
And no, they weren't brought in at night.