Why does brutus and cassius take their own lives at the end of the tradey of julius caesar

Brutus and Cassius take their own lives at the end to not be captured by the enemy, Brutus realizes that him and his servants would be captured so he convinces Strato to hold his sword as he takes his own life. Cassius knows he will be captured by Octavius and Antony, which he will then be dragged down the streets of Rome in chains. He orders Pindarus to do the same thing Strato did for Brutus.