Each holder of $PIR or $MEG can attack others via ATTACK APP. You will have to connect your Metamask wallet with $PIR or $MEG on it ( or BUY them if you don´t have ), select the quantity and unit that you want to use for the attack, indicate the wallet which you want to attack and launch your warriors.
Piranhas killed by your attack will be placed in a freezer for a certain amount of days, depending on how much energy you have for the attack. After the freeze period is over, piranhas will be returned to the owner's wallet.