Answer:
When Patroclus came to the battle and the men of Troy beheld him, they thought that Achilles had forgotten his anger and come forth. Then the men of Troy turned to flee, and many chiefs fell by the spears of the Greeks.
"Sudden as hungry wolves the kids purloin
Or lambs, which haply some unheeding swain
Hath left to roam at large the mountains wild."
Homer compares the Greeks to hungry wolves who attacked the lambs which were left unsupervised. By lambs, the author means the Trojans, who bacame easy prey for Greeks after Patroclus in the armor of Achilles charged them.