Kids of all ages- not just for little humans. They are for people who love the great outdoors and/or love to stretch their imagination through open-ended construction.
We recommend diameters between 3/8" and 1 1/4" (10mm - 32mm).
Sticks are almost everywhere! Check out your local park, the sidewalk and the forest. Sticks are plentiful after storms and during seasonal shifts when trees shed their branches. Bamboo makes an excellent building material as well. 
In the US: Home Depot and Lowe's carry a few variations of dowels for you to choose from. If you ask nicely, they will agree to cut them to the length of your choice. Your local art supply store may also have them. If you need large quantities, visit Mcmaster-Carr.

In Canada: Large quantities can be purchased from Bearwood.

In Australia and New Zealand: Large quantities can be purchased from Bunnings, Masters, and Mitre 10.
Of course! Stick-lets are made from 100% silicone, which means that they are non-reactive, stable, and resistant to extreme environments while still maintaining their useful properties. They also maintain their original tear strength after multiple uses. Please do not leave these behind in the forest. We made them brightly colored so you can find them.
Yes, Stick-lets are safe for children and the silicone is RoHS compliant and provided the CE marking. However, we still don't recommend you swallow them. They were made by an ISO certified, child labor-free manufacturer. The tote bags are made from all-natural, unbleached muslin, printed with non-toxic ink.
Stick-lets are designed to grow with the user. If your child does not need them for fort building anymore, try using them for gardening or camping. You can also use them to make simple indoor furniture- like a coat rack! If you prefer, you can donate them to your local school or camp program, or even your workplace for team building exercises.