> One squirrel shouldn't be able to bring a whole grid down. Grids are supposed to be resilient and have a couple of safety features

A very big outage in North America occurred from the cascading effects of a single breaker working as intended. The grid is a very complex system because it is dynamic and subject to states of vulnerability that may not be well understood.

Yes but it was not "just the squirrel" it is a combination of factors (usually faults or overloads upstream).

Exactly my point, the grid is a complex dynamic system.

Something being a complex dynamic system doesn’t make it vulnerable to squirrels. It may be vulnerable to squirrels, but it also may not be.

Link for anyone who didn't know about it: https://en.wikipedia.org/wiki/Northeast_blackout_of_2003

For sure but in the interest of national defense seems like we should work to amend that