The phrase "little clumps" refers to small groups or bunches of things that are stuck or grouped together.
Sentences with «little clumps»
Little clumps of neurons growing on tiny spaces on a microchip that can control their growth and measure their responses. (en.hdbuzz.net)
But computer simulations suggest that dark matter that doesn't interact with itself would form myriad little clumps that are very dense in the center. (sciencemag.org)
Because milk paint is powder that you mix with water, and because I mixed mine by hand (with a small fork), I saw quite a few little clumps as I painted it on: (theletteredcottage.net)