I have been loosing seedling to squirrels. I have not seen them, but since they started with the broadies I am assuming it is them. After I netted the broadies, they started on the sunflower seedlings and broccoli. The broccoli was more or less ready to plant outside so a real pain.
I have finally found a good move, I have found my small module trays with 12 modules fit nicely into the netting bags which supermarkets sell for vegetables. Hopefully they will not learn to chew through the bags too quickly.