I recommend Red Wriggler Worms (Eisenia fetida).

The best way to keep them is in a plastic container (40 Gallon or so) with demisions of 2ft deep x 3ft long x 1.5ft wide. They do not require deep soil.

These worms consume roughly 3-4lbs of organic matter per week, and will start to breed in under 3 months.

Though they only grow to a maximum of 1.5”, they make up for it with their quick and easy breeding!

Hope that helped!

~Royce