**Short answer**  
Cockroaches are an integral part of the food chain. 

**Background**  
Cockroaches are an important **source of food** for a number of organisms, such as arthropods, birds, and mammals. As such, they are an important part of the food chain. Cockroaches also play an important role in **nutrient recycling**. Most species of cockroach are **detritus feeders** and with the help of endogenous cellulases play an important role in degrading plant material. Some species, such as Cryptocercus, feed directly on wood and play a major role in lignocellulose digestion in temperate forests.

**Reference**  
[Bell et al., *Integr Comp Biol*, 2008; **48**(4): 541-3][1]


  [1]: http://icb.oxfordjournals.org/content/48/4/541.full