I got this crazy idea to maybe try using my old tea strainer to aid in making a perfectly round felted bead. Here it is with a small pile of mixed roving colors.
Roll up the roving like you would pack something fragile in paper - roll it up, then roll the sides in, roll some more, roll the sides in, etc., until you have a nice compact ball of roving.
Put the ball gently in the tea strainer.
In very hot, very soapy water, swish the tea strainer fast in a circular motion.
Shock it by running under very hot water. With children, just make the water a temperature that is comfortable for them. Alternatively, use rubber gloves.
Add a drop of soap directly to the ball of roving in the tea strainer, close, and
swish around, very fast, in a circular motion. I repeated this step a couple times.
When I removed the ball from the tea strainer it was beautifully spherical. But not felted. I very gently rolled the ball between my palms until it started to felt.
I shocked it with hot water.....
and repeated the process several times of dipping in the soapy water and rolling around between the palms, rolling it harder the more it felted, sometimes adding a drop of soap directly to the ball.
Voila! A nice, spherical, hard felted bead.
Oops, I guess I should have measured the roving more carefully, to make the beads the same size.
Measuring the roving is best done by weighing it on a fine scale, which I don't have. But lacking a scale, the best way to make beads the same size would be to lay out your roving for the number of beads you want to make, each having its own pile of roving. You can then eye-ball the piles of roving to make them each the same size as the next. Hopefully, your beads will be very nearly, if not exactly!, the same size.