Set in modern day, a small warren of rabbits randomly achieve sapience in an unremarkable, rural countryside. These rabbits become capable of thinking and self-reflection, as well as advanced teamworking and organisation. They could use tools, but its difficult to craft or hold anything with paws. Otherwise, they live as rabbits live. They are incapable of speaking any human language (incompatible vocal cords), but they do have a language of their own.
Although intelligent, they are still unlearnt and their society is primitive.
Any offspring from this warren is sapient as well, but all other rabbits remain just animals. The warren is capable of expanding at however fast rabbits breed.
Rabbit hunting and snaring is still popular among the farmers living nearby the rabbit's territory. As such, the rabbits develop a deep fear of humans and try to avoid them.
How long would it take humans to realise that this rabbit community possesses sapience?