Germs: We can’t see them, but they’re literally everywhere. And that’s not necessarily a bad thing. Kids need to be exposed to germs to build their immune systems; plus, a hyper-clean environment has been linked to kids developing conditions such as asthma and eczema.

But where would you expect the most germs to live in your house? A recent study of family homes looked into this, and the answer totally shocked us.

The website ASecureLife measured the amount and type of germs on 10 different household items that kids regularly come in contact with. Most parents guessed that their smartphone and TV remote would be the germiest. But these items didn’t even crack the top four. In fact, the No. 1 germiest item was…wait for it…the stroller! This was followed by sippy cups/pacifiers and, strangely, plush toys. Each had more germs than the average bathroom floor!

Many of the strollers tested for the study were found to be growing the streptococci bacteria, which can cause illnesses like strep throat, pink eye and meningitis. The worst areas were the stroller’s handles and cup holders. But why would strollers have so many more germs than other items? The study authors say it’s because many people store their strollers in garages, which experience more temperature and humidity variation than most other places in the house. The garage also traps in dust, exhaust fumes and germ-carrying pests, creating the ideal breeding ground for bacteria (as well as yeast and mold).

Coming in at No. 2 most germy were pacifiers and sippy cups, which were found to sometimes contain E. coli and salmonella. These germs were most often found in the nipple or spout. As for plush toys, researchers found listeria growing on one; contact with this dangerous germ can potentially cause listeriosis, a rare but potentially lethal foodborne illness that can affect people with weakened immune systems. Listeria is typically found in soil, sewage and untreated water, as well in a variety of common foods like fish, meat, dairy products and fruit.

Other interesting findings from the study:

• Board books and diaper bags were also found to be quite germy.
• Homes with one stay-at-home parent had significantly fewer germs than homes with two working parents.
• Homes with pets didn’t have higher germ counts than those without.
• Kids aged 3 to 4 had items with the highest germ counts.

It’s worth noting that this research was conducted on a small sample size that does not necessarily represent the general population, and that a similar study with a larger sample size may produce different results.