We cannot be home 24/7, although in an emergency situation, (hurricane, economic disaster, etc) it is recommended to do so. If you have stored 3-6 months worth of food, or you have a good stockpile of weapons and ammo it's generally a good idea to guard it with your life. If an intruder is allowed enough time, even the best hiding places are vulnerable. None of these ideas are free to implement, but at the cost of losing your investment in food and protection, may be a necessity.
1. Behind the wall. - Between every stud in your home holding up the drywall is anywhere from 16 to 18 inches. Tear down the dry wall and build some shelves with properly sized 2x4's. The weapon(s) you don't carry every day, ammunition, and canned foods can be hidden in the interior walls until you are ready to use them. Remember this is a "one-off" use hiding place as you don't want to be replacing drywall every time you get hungry. Replace the drywall with some drywall mud and tape, then put wallpaper over the hiding place.
2. Beneath the floor. - In some homes, this isn't an option but most two-story homes have a layer of insulation in between floors. Reinforce the plywood separating floors and store your goods there. A couple of things to remember about floor hiding spaces. First, you don't have to make the door into a cartoon-like ancient wooden door with the huge ring denoting the "Secret" spot. This isn't Scooby Doo. Second, a thick enough pad and carpeting can reduce chances of the intruders finding your stash.
3. Under Ground - As long as there are no nosy neighbors spying into your back yard, you can dig a decent sized burial plot for your canned food and weapons. "What if they dig?" you may ask. One way to disguise the intent of the holes is to place a cheap stone monument to your dog, "Mohammed" or "Spot", the last thing crooks want to do is to dig up a dog's remains. Use a coffin shaped box nailed tightly shut. Choose a spot under your garden to give reason for freshly dug dirt. Or plant sod over the spot and let it grow. Use a 3 inch PVC pipe to contain jars to prevent breakage when digging them up.
4. Alter a closet - Only you know how large and deep your closets are. Create a storage area by cutting off a portion of your closet space using drywall. Make them look legit by hanging clothes in the smaller area over the new wall. Some homes have a large space under the stairway, store what you can there and replace the door with a wall.
5. Rent a space - Storage lockers abound and while some are outrageously priced, there are others that are quite reasonable. This give the added advantage of having somewhere to store food and ammo in case you had to bug out of your location without a chance to get home. Preferably this will be a location that is on the way to your bug out area.
6. Beehive safe - For those of you with your own colony of bees, congratulations. Build an extra hive to store stuff in and place it close to the active one. Make sure the entrances are blocked off so that you don't end up with bees actually living in there. It would serve to give a thief pause before tearing into a beehive for treasure. And if they did find it, they may not be able to tear themselves away before ripping into the active hive, which would yield hilarious results for you.
7. Septic tank safe - NO! do not store food in an actual septic tank. That should go without saying but... Get a new small tank and bury it as if it is an actual septic tank. Cut a hole in the top large enough for you to work with, store your stuff and seal it up with a larger door.
8. Freight Container - EXPENSIVE, but worth it. A freight container could actually be used as a combination storm shelter, food and ammo storage. Read up on reinforcing the top and sides and bury the container with a "secret" door. Don't forget ventilation in case you want to use it as a shelter.
Remember that for areas with harsh winters, burying or uncovering food and weapons may require waiting until spring. Don't tell anyone (except a spouse) [unless he/she talks a lot] where it's all at.