Is there any benefit to having the pre-exposure rabies series for a possible bat bite 2.5 months ago? er won't treat me because of how long it's been.

Pre-exposure ?????: Pre-exposure series are taken by those in high risk professions with likely contact.Post-exposure series is actually the same shots but given in a timely matter as soon after the bite as possible.The vaccine is quite pricey and production is limited.You might find a private clinic to give it to you if you pay up front. Don't expect an ER to give it if you don't fall into their treatment guidelines

Unlikley: I think you mean post exposure. The current CDC guidelines do not recommend immunoglobulin after 7 days but the vaccine could be given however 2.5 months it is very unlikely that you have the disease without symptoms. I would contact your local public health department for local policies as there are VERY RARE cases of prolonged incubation out to 2 years in humans.