You know that ratty red kitchen sponge? Many experts label sponges as Public Germ Enemy #1 in your home. Household bacteria carriers in general can make you and your family sick. To help, we asked experts how to zap the top five culprits. Here’s what we found.

1. Kitchen sponges and cloths

The problem: Food particles from last night’s dinner cleanup are still clinging to your sponge or dishrag, but that’s not the main problem. It’s the moist environment that makes it a playground for bacteria to grow and multiply.

The solution: Change your sponges regularly. How often? Go by appearance. If your sponges are starting to shred or look grey, pitch them and buy new ones. “Also identify separate sponges for separate jobs – one sponge for dishes, another for cleaning counters,” says Patricia Mail, president of the Washington-based American Public Health Association. This helps to stop cross-contamination. “If you have a dishwasher, drop your sponges into the upper rack when running a load through.” Or, you can toss your damp sponge in the microwave and nuke it for 30 seconds to kill off any germs. Wash dishrags in the washing machine on the warm cycle and dry in the dryer.

2. Cutting boards

The problem: Cutting boards are used to prepare a variety of foods, including raw meat which can contain dangerous, make-you-sick bacteria such as salmonella. Also, if you’re not washing your produce thoroughly before cutting, the bacteria clinging to your broccoli or strawberries get transferred to your board.

The solution: Keep separate boards — one for meats, another for produce — to avoid cross-contamination. “The raw meat board needs to be sterilized, so rinse it in the sink, and then drop it in the dishwasher,” says Mail. (Don’t forget to clean your sink afterwards with bleach and soapy hot water too.) No dishwasher? Wash the board with a scrubber in hot, soapy water, and then spritz with a bleach/water solution (use one teaspoon of bleach to one quart of water) to sanitize it. Rinse off the solution and let the board dry thoroughly before you put it away (germs thrive in moist environments). If your board is cracking or developing deep grooves, toss it and buy another — those grooves can harbor bacteria. And don’t worry about whether or not you have a wood or plastic cutting board, both are fine as long as the proper sanitary precautions are taken.

3. Toothbrushes

The problem: Our mouths are full of bacteria, which can transfer to our brushes after a cleaning. Brushes are also often sitting out on a shelf our counter, so if you’re washing your toddler’s hands post-playdate, for example, splashes can hit your toothbrush.

The solution: Allow the brush to air-dry between brushings in a drawer or medicine cabinet, not on the counter or near items like cleaning products that can get onto the brush. “Also, a good hot water rinse after brushing never hurts,” says Eleanor Wilson, president of the Ottawa-based Canadian Public Health Association. “But also remember to change them every few months, and after someone’s been sick, particularly if it’s gastrointestinal.”

4. Computers and cell phones

The problem: Bacteria left over from handling food, suppressing a cough or changing the cat litter can all get deposited on these common household devices. Cell phones, hand held organizers and TV remotes are in this same category.

The solution: “Hand washing is key,” says Wilson. So do it often. (Tip! Use soap and hot water and sing ‘Happy Birthday’ twice in your head — about 20 seconds — to ensure you get a proper lather and rinse.) Wilson also suggests keeping alcohol-based wipes on hand to wipe down phones and keyboards when needed. Avoid antibacterial-based wipes though because using them too often can contribute to the resistance of some bacteria.

5. Pets

The problem: Pets carry bacteria from playing, walking and eating outside, notes Mail. If your kitty creates an outdoor litter box, for example, or your dog investigates something dead and rotten, all kinds of bacteria gets tracked into your home on paws and fur.

The solution: If your pet has fur, brush it regularly to help move dead hair, which can harbor dirt and bacteria. Wipe your pet’s paws when it comes in from outside. And remember your own hygiene, says Mail. “Don’t kiss pets on the mouth — dogs eat anything that’s on the ground,” she says. “Wash your hands after handling a pet.”