The 9 Best Spy Kits For Kids

Kids who want to crack a case the way a crime lab would get the most from the Spy Labs Master Detective Toolkit. It packs fingerprint dusting, plaster casts for footprints, invisible ink and a UV flashlight into a hard carry case, with a storybook that leads them through more than 20 activities. Science Focus named it a top spy toy. The flashlight needs a AAA battery that isn't in the box, and some kits arrive with a flimsy brush.

For backyard missions rather than lab work, the SpyX Micro Gear Set hangs four small gadgets on an adjustable belt: a light that clips over the ear, a pen with invisible ink and a UV tip, a motion alarm and a listening gadget that boosts nearby sounds. The maker rates it for kids 6 and up. The plastic is light, so rough play can snap parts, and the ink pen sometimes shows up dried out.

The National Geographic Spy Science Kit turns spying into a paper trail of 10 missions, each sealed in its own envelope. Kids peek around corners with a periscope, watch what's behind them through mirrored glasses, spin decoder wheels and write with an invisible ink pen, then log clues in a secret notebook. The guide also tells stories from real spy history. Much of the kit is paper and stickers, so it has less to offer once the missions are done.

Children who like test tubes as much as secret codes should look at the Spy Labs Forensic Investigation Kit. It sets up a small crime lab with a tool rack, filter paper, pH strips, fingerprint powder and a UV flashlight, plus a bit of horse chestnut bark that glows blue under the light. The manual shows how investigators separate inks and identify mystery liquids. There's little here for running around, and the powder gets messy, so work over a tray.

After-dark games are where the SpyX Night Ranger Set shines. Its goggles carry two bright lights and a flip-down scope, and the set adds a motion alarm, an invisible ink pen and a voice changer that records a short message and plays it back in a disguised voice. Be clear with kids that the goggles are headlamps, not true night vision, so they light up a dark room rather than see through it.

Long car rides and quiet afternoons suit the Melissa & Doug Secret Decoder, a screen-free set of puzzle books, decoder wheels, color-change markers, an invisible-ink marker and a magnifying lens. Kids crack codes, hunt for hidden pictures and write notes that only a friend with the right marker can read, across more than 50 activities. It suits early readers. Once the books and stickers are used up, the fun is mostly over, and there are no gadgets.

Young builders get a real project from the Klutz Ultimate Spy Vault, which has them assemble a plastic safe that locks with a key and wire up a buzzer that sounds when someone opens a door. The book that comes with it explains how the circuit works and adds code puzzles to hide inside the vault. It's a craft first and a toy second, and many kids will need an adult for the wiring.

The 4M KidzLabs Fingerprint Kit is a cheap way to find out whether a child enjoys forensic work. It covers one skill well: taking prints with an ink pad, dusting for hidden ones and lifting them with clear stickers onto record cards for a suspect file. A plastic case keeps the brush and powder together between sessions. It does only that one job, and the lifting stickers run out, so keep clear tape on hand.

With the MindWare Detective Lab, a curious kid works through seven short forensic experiments: lifting and comparing fingerprints, writing secret messages, separating ink colors on paper and testing liquids with pH strips. A colorful guide gives step-by-step directions and safety notes, and it ends with a code to crack. The experiments go quickly, and supplies like the test strips are used up after a few tries, so the fun is short.