What do you mean, counterargument? A "counterargument" can only exist relative to an argument. So far there hasn't been an argument. To recap: 1. "A big reason

What do you mean, counterargument? A "counterargument" can only exist relative to an argument. So far there hasn't been an argument. To recap: 1. "A big reason bats carry a lot of diseases is that they have large temperature fluctuations." 2. "How does the one lead to the other?" 3. "Diseases can't tolerate temperature fluctuations." That's gibberish, not an argument. Combining two random (or in this case, contradictory) sentences doesn't make an argument.