What limited resource prevent decomposers from growing out of control?

The answer is Tamed Fungi.

Explanation:

The new, unidentified types of Cordyceps transforms people first into brutal "tainted" and after that into visually impaired "clickers," finish with fruiting bodies growing from their appearances. Like customary zombie standard, a zombie nibble is demise. In any case, the inward breath of Cordyceps spores is the un-demise sentence.Humans likewise intentionally reproduced canines to be more lovable. Different pets came later. Sheep and goats were first tamed approximately 11,000 years prior, while felines moved toward becoming pets around 7000 B.C. with the coming of horticulture.

answer: because barriers look like ball

explanation: there round and blue like my ball