Can squirrels get into sealed plastic containers?

I'm about to wintersow for the first time. I've saved clear plastic containers with snap-on lids from grocery store salad greens. There is no place I can put them where there aren't squirrels. with the lids snapped on tightly, will squirrels be able to get into them?

Anne, I'm a first time wintersower as well, and I'm surrounded by mature oak trees, feral cats, birds, raccoons, and big fat squirrels. I'm using gallon jugs, 16-24 oz water/soda bottles, and take-out soup containers. I placed them away from the usual squirrel-digging areas, and they've been left alone.

If there is food involved then they can chew their way through metal flashing (the kind under roof shingles), wire (Xmas lights), plywood, and five gallon plastic buckets that store bird seed.

I've got those sorts of containers for my winter sowing as well, Anne_Louise, along with milk jugs, and I've never had problems with squirrels getting into mine. Please let me also say that I have squirrel problems here and always have. I have NEVER been able to grow tulips because the bulbs always get dug up and eaten by squirrels. Not only that, but my lot is surrounded by trees in which there are tons of squirrel nests, so I've always got tons of squirrels around here. I even had one come up on the deck this morning while I was eating breakfast. I looked over at the sliding glass door, and there was this little critter standing there tapping at the door for me to let him in. ACK! Well, my deck is where all my winter sown containers are, along with potted bulbs, and they are perfectly fine and untouched, so I would say your containers are *probably* safe as well.

I had bird seed stored in a thick plastic trash can and the squirrels chewed through the lid in about two days. I replaced that with one of those shiny metal trash cans and even though they keep trying, so far they haven't been able to penetrate it. A thin plastic container will take squirrels about five minutes to chew into.

Oh yes, hrp50, and it takes about 6 minutes for 'em to chew through a thick plastic one! =) I think the big thing though is, how badly do they want to get at what's inside? So far in my experiences, they (or, at least the ones here) don't seem to want to get at the winter sown seeds. Not much to eat there, I suppose.
I should have noted that, the potted bulbs on my deck are laced with hair from my hairbrushes. I have heard that human hair is a good deterrent, due to the human smell, so I've got it in ALL my potted bulbs, even the ones sitting on the ground out front where the squirrels behave the worst, and so far so good.

It'd be interesting (fun?) to do an experiment; put something enticing in one sealed plastic container (something like bird seed or nuts), and a regular soil/seed combo in the other container, and see what the squirrels will go after. I'd try that, if I weren't so gung-ho on getting rid of the darn squirrels in my yard. .... maybe I could try it in my neighbor's yard? < =D

I lost a whole stand of corn in a 4' x 4' raised bed last year just about the time the cobs were ready to pull. I want to try it again this year, maybe with a 8' wood and wire removable frame cover, but I'm not sure it will deter the squirrels since they can chew through the wire. Right now I'm reading a book entitled "Outwitting Squirrels: 101 Cunning Stratagems to Reduce Dramatically the Egregious Misappropriation of Seed from Your Birdfeeder by Squirrels" by Bill Adler Jr, but it doesn't seem to have very good answers to the problem.

Hrp50, does it have any suggestions for keeping the egregious little pests out of garden beds? If so, I'll buy it pronto! =)

Squirrels are cute to watch but they are rats with bushy tails! My neighbor has one of those heavy duty patio/deck storage units he keeps his bird and squirrel food in. They were either watching him or they smelled it but they ate and chewed right through the door to get to their tastey treats! So no, your plants will not be safe...so sorry.