Sunprints (or cyanotypes, or photograms) are everyone's favorite photo-sensitivity experiment, from third-graders to graphic artists and fine artists. You pick: The Sunprinters are a dozen 3-15/16" square sheets of photosensitive paper, an acrylic backing sheet and instructions. The large Sunprint Kit has (15) sheets of 12" x 7-3/4" photosensitive paper plus a clear acrylic sheet of the same size. Great for classroom demonstrations, and can be used to make prints from photo negatives as well as interesting effects from opaque or translucent objects. All you add is sunshine and water.

Much better than a box of rocks, because fossils are more fun. You get (10): a trilobite, nautiloid, goniatid, petrified wood, coral, ammonite, dinosaur bone, sea urchin, shark tooth and a brachiopod, all in a handy storage case. Also comes with a fact sheet explaining what the mysterious ones were when they were alive. Also a free little fossil-inspection magnifier.

You can’t put science on a stick, but you can put it in a can. The Crazy Scientist™ lab kits for young researchers come from The Purple Cow® in 6-1/2” x 9-1/2” x 1-1/2” tins. You pick from: The Water Gel Science Kit for ages 8+ with (14) experiments, lots of supplies and a 15-page manual; the Magnetic Wonder Kit for ages 8+ with a variety of materials and a 20-page manual; the Optical Illusion Kit for ages 6+ with (13) experiments, supplies, nd a 28-page manual; or the Young Survivor Kit, for preppers as young as 6, with (13) projects, equipment, and a 20-page manual.

From Metal Earth®, the people who make shiny metal 3D models, now comes the Doctor Who metal models. All punch-outs with no glue or soldering required. You pick: the Golden Dalek, at 2-1/4” x 3” x 1-1/4”; or the Blue Tardis model at 1-5/8” square x 3-1/4” tall. And if you don’t know what a Dalek or Tardis  is, you shouldn’t even be reading this. These are challenging models, so rated for all ages over 14.

Why does it do that? Develop an elemental understanding of magnetism, electromagnetism, electrochemistry, radio, thermodynamics, light and optics. Simon Quellen Field's 228-page paperback, Gonzo Gizmos, Projects & Devices to Channel your Inner Geek explains processes, equipment and scientific terms -- and then, for starters, tells you things like how to make a rotary steam engine in 15 minutes from a soda can, a candle and a few scraps of rubber tubing. It's the favorite of our resident geeks -- but not for kids unless they're working with an adult. That would be a mature adult. An insured, mature adult.

From Fascinations®, these small model kits are made from intricately laser-cut polished steel. Punch the pieces out from the 4-1/4" square sheet and put them together with the tiny tabs. You pick the dragonfly, with a 4-1/2" wingspan or the Black Pearl pirate ship, approx 3-1/2" long. For ages 14+, because they take plenty of small motor skills.

In the mood for a little light levitation? Try this magnet-based kit from KidzLabs® and make a pencil float in mid-air or tell your fortune, all through the captivating power of magnets. You can even build a mag-lev robot, and who doesn't want one of those? The (7) projects are based on the (7) plastic-coated, 1-5/16" dia bored disc magnets and assorted other parts. Projects include anti-gravity sculpture, floating spinner, magnetic compass, spring and weight scale, propelling machine and a mag-lev transporter.

Meet the STEM-friendly hydraulic gearbot. The completed, syringe-driven device will stand a foot tall and involve a completely unnecessary but fascinating series of gears and levers to hurl a projectile from the basket on the top arm. In dye-cut plywood, it takes an hour or two for an 8+ year-old. Includes all parts. All you add is patience and water.

Cleverly made, and mighty heuristic, too. For someone entranced by hydraulics, or for a whole classroom of students, there's the Pathfinders 4-In-1 teaching kit, with 4 different hydraulic-system kits that use unfinished wood, transparent tubing, and plastic syringes, which power the movement. The mini models include an excavator, scissors lift, cherry picker, and platform lifter. Bases are approx 4" x 7" and finished heights vary, thanks to those syringes! Very clever teaching tools for ages 8 and up.

Including bubbles as big as your grandmother. You get 2 oz of fluid; (4) straws; a mouthpiece; cubical, pyramid, star and round frames, 108" of yarn (for the bubbe-sized bubble); a tray and instructions for (11) kinds of bubble activities.

Triops: way cooler, bigger and more active than sea monkeys. They're dinosaur shrimp, leftovers from some 200 million years ago. Don't eat them; just grow them and enjoy this bizarre & ancient display of nature! In the kit you get a kidney-shaped tank 2-3/8" tall x 8-1/2"x 5-3/4", a very informative instruction booklet, and a packet full of triops eggs and food. In the starter pack/refill pack you get tripos eggs, food, conditioner and directions. Add the eggs to water and watch them go; they'll hatch in a day and reach 1" to 2" or more in a few weeks. Really easy to do, and really cool too.

It's kinda pretty, and pretty simple, this old-fashioned rubber band-powered boat. Wind the paddle, watch it ride the waves, or bathtub. Measures 5-3/4" x 2-1/2"x 11/16" in varnished pine and even comes with spare rubber bands.

Could be lilliputian versions of Heidi Klum and Naomi Campbell, but they’re not. They’re dandy little 37-piece (mostly) steel model kits of two different racers, a biplane or a helicopter, from Steel Works. Finished models will be a couple of inches long, and a tiny tool for assembly is included. We’ll pick one that will be just right for you. Ages 8+.

From Creativity for Kids®, these DIY kits call for assembly and decoration, and have everything you need, including glue, paint and brushes. You pick: the Bitty Bobble Duo is a pair of 3” tall bobbleheads, a kitty and puppy, for kids age 6+; the wooden Pirate Ship has a Jolly Roger sail and will be about 6-1/2” long when done, for ages 5+; the Shrinky Fairies are a trio of 4-1/2” tall fairies with a birds and flowers backdrop, and is for ages 7+ with adult supervision for the shrinky baking.

Knot everyone knows how much fun knots are. You can join the knot knowledgeable with Knots, Splices and Rope Work an 88-page soft-cover book originally published in 1917. Includes detailed instructions for tying many dozens of knots, ties, bends, hitches, loops, nooses, lashings, seizings, splices and things like the Matthew Walker, Selvagee Tie, Flemish Eye and the Topsail-Halyard Toggle. Includes (4) pieces of nylon rope for practice. Will tie up a kid for weeks.

For the steady-handed model-maker. These mini-models from Metal Earth® are demanding and beautiful. Use a tweezers to punch out the little pieces from the laser-cut shiny steel sheets, and assemble them using the tabs and slots--no glue, no screws. You pick the Hubble Telescope (3” x 2” x 2-1/2”), the U.S.S. Arizona (5-3/4” long) or the 1908 Ford Model T (3-1/2” x 1-7/8” x 1-3/4”). All include instructions, which you’ll need. For ages 14+.

Or maybe not. Hotel managers get funny about rocket launches, but this is NASA-level fun for the backyard, or maybe a cheap motel parking lot. The Stomp Rocket™ uses no batteries, fuel, diet cola or anything else but your feet. And good stomp on the 4" X 8" "Blast Pad" can get you 200 feet of lift at speeds up to 100mph. You get (4) bright yellow plastic rockets, 9" long x 7/8" dia, with soft, round nose cones (bulbs?) for safety's sake, and a tripod gantry. Fine adjustments even allow for accuracy contests. If the neighbors have really high roofs, or you manage to achieve orbit, we've got a (2) pack of replacement rockets.

The entomologist’s friend. This folding insect cage, which is the same as our butterfly-net kit, is made of nylon-mesh, and measures 10” dia x 11” tall when popped open via the interior steel spring. A pair of hook-n-loop straps keeps it flat when not in use. Includes a basic teachers’ guide.