When Beatrice and Benedick bicker they suggest that what are living individuals?

Beatrice and Benedick, in their witty banter, suggest that words are living individuals. They personify words, giving them agency and even emotions, highlighting their playful and often ironic nature.

Here's an example:

Beatrice: "I wonder that you will still be talking, Signor Benedick: nobody marks you."

Benedick: "What, my dear Lady Disdain! Are you one of those that would have one, as he is, and then, after he has lived a little while, say a 'little more', 'a little more', till he becomes nothing but a little more, and then 'what's that?'"

Beatrice: "Are you so hasty, that you would have me marry you this afternoon?"

Benedick: "Why, even now, tomorrow morning."

Beatrice: "And why not to-night? I am ready, I'll go to church and have him presently."

Benedick: "But wait a little; you must consider your time. To-morrow, my dear Lady Disdain. To-morrow, will serve for all numbers."

Here, Beatrice mocks Benedick by implying that his words ("a little more", "a little more") are like living beings, growing and changing until they become meaningless ("what's that?").

This personification of words underlines the witty and clever nature of their conversation, and it also suggests that their bickering is a game they both enjoy playing.