Bedbugs in a Rental. What to do with the deposit????

[Matt Nico]

Hi Everybody!

So I rent my house out by the room in Florida. On the 1st of the month, 1 of the roommates left, and was replaced by another. Yesterday (the 5th of the month) I got a call from the new tenant who says the room has bed bugs. She even captured one in a zip lock bag. I called an exterminator who came by the same day and is telling me the bed bugs have not been there long. Probably a few weeks to a month. 

How should I approach keeping the old tenant's security deposit? Should I trust an exterminators word and assume the old tenant has bed bugs, or it could be possible that the new tenant brought them with her.

Thanks in advance,

Matt