When you step on a cóckroach, all of that white stuff that comes out is basically its body fat or 'fat bodies'.
Similar to fat stores in humans, fat bodies allow cóckroaches to store energy after nutrients have been broken down.
The fat body participates in myriad metabolic activities and functions. Absorption from hemolymph and buildup of intracellular storage nutrients in the form of lipid droplets, carbohydrate (glycogen) deposits, and protein granules during the immature stages are aimed at accumulating reserves for later stages and primarily to serve adult activities.
Fat body cells, having homeostatic functions related to metabolism, respond to nutritional and hormonal cues that regulate and modulate blood sugars, lipids, and proteins at larval and developed stages.
Learn all about cóckroaches, facts about cóckroaches and different types of cóckroaches at Pestworldforkids.org.