The next time your baby seems to find an endless source of energy for a tantrum, you can only blame yourself. After all, you might be feeding the little tyke rocket fuel. A study the Centers for Disease Control and Prevention released earlier this year found that each of 15 baby formulas the CDC tested contained some amount of perchlorate, a key ingredient in rocket propellants. These results sound terrifying, but although high levels of perchlorate can potentially inhibit thyroid function, none of these formulas contained an unsafe amount of the naturally occurring chemical. This discovery might, however, explain the speed with which babies can crawl.