Franco Mason has written:

'The Afrotropical Nemotelinae' -- subject(s): Stratiomyidae, Identification, Classification

Yes, maggots are among the organisms that may be found in compost bins. The insects in question represent a larval stage that consumes nitrogen-rich layers of compostables and recyclables and helps break down organic matter. The larvae mature into soldier flies (Stratiomyidae family) that encourage beneficial bacterial presences in compost bins.