How can one reconcile the excellence of a swift death and the abundance of ants when dealing with them in cleaning, waste disposal, and when water is splashed upon them?

The Prophet, peace and blessings be upon him, forbade the killing of ants unless they were harmful. According to Sheikh Ibn Uthaymeen: "That which is forbidden to be killed should not be killed unless it causes harm, in which case it should be repelled by the easiest means. If it cannot be repelled except by killing, then it may be killed." Kindness in killing harmful ants should be by any possible means that does not involve torture, for the Prophet, peace and blessings be upon him, said: "Indeed, Allah has prescribed excellence in all things; so if you kill, kill well."