Army worms!
 

For the last two days we've had literally battalions of army worms
marching in a southerly direction through our property.
From what I've read, they are mainly pests of grasses and grains and
so far they don't seem to be bothering any of our vegetable garden
plants.
I also read that a count of 5 per square foot is the threshold for
control measures to be instituted in vulnerable crops. In many areas
here I've counted 10 or more per square foot.

Ross.
Southern Ontario, Canada