JPL was established by the California Institute of Technology and is a laboratory for NASA. They hold an annual Open House for the public. I attended for the first time this year, but did not see this sign or said rodent. Bummer. I did, however, see a deer run down the hill amongst a decent amount of visitors. Rocket science is cool. Attack squirrels? Not so sure.
*Photo used by permission from the awesome heathervescent.