An 80 year old male in the US has a life expectancy of 8.4 years[1]. That's a lot of time to bet, especially since "aggressive bat" is almost certainly rabid.
That said, daytime flying, obvious sickness, and aggression/biting are all symptoms of likely rabies in bats.
Not nice, but not really worse than many other modes of death - at least superficially. We do not know what happens in the sedated brains of the patients in their last days.