This is actually quite a popular question. Take a look at this answer specific to Cannae:

• After a gigantic battle like Cannae that left a huge amount of dead bodies in a relatively small area - was this viewed as a health risk? Would the place be generally avoided and how long it took for it becoming a part of a normal route of travelling people again? by /u/PapiriousCursor

For answers more general to the ancient and medieval world:

• Stripping Enemy Armour in Battle, e.g. The Iliad by /u/XenophonTheAthenian, /u/70charger, and /u/Agrippa911

• Watching GOT I got wondering about battlefields by /u/Valkine

• Were corpses stripped or buried with dignity after a battle in, let's say, 15th Century Europe? by /u/MI13

• After a certain side won a medieval battle, what would happen to the bodies and the other army's equipment etc? by /u/Trinity-

For answers about the modern era, if you're interested:

• Who cleaned up the bodies on D-Day? by /u/eternalkerri

• What happened at the battlefields shortly after major WWI battles such as the Somme, Verdun, etc? by /u/DuxBelisarius

• With hundreds of thousands soldiers dying in battles on the Eastern Front, what happened to their bodies? I assume it was too cold to burry them and they would be preserved by the cold. So did they burn the bodies or when Summer came were there suddenly thousands of decomposing bodies? by /u/Acritas and a deleted user

• How did the french clean up verdun after WWI? What was the process, and are there any period photographs comparing the area directly after the war to post clean up? by /u/CrossyNZ