I'm not sure you can form an effective strategy against the critter when you don't really know what it is. I think I would guess lights wouldn't keep ANY critter away though. Why would they?

How ripe are they? You could start picking them right as they start to blush.

Jenn

The easiest solution is as wormgirl said - pick at the breaker or blush stage. Common practice and the fruit gains nothing from the plant beyond that point anyway. Ripen them indoors on the kitchen counter out of direct sunlight where you are the only critter that can get to them.

Dave

I third : Pick them at color break.
as Dave said : the fruit gains nothing from the plant beyond that point anyway.

Ripening ( after certain stage) is an internal process in the fruit. it happens in a lot of fruits including tomatoes. At that stage the stem becomes woody and almost dry and you would need a sharp pruner/knife to cut it.

Sey

An alternate thought is, if you have a wildlife camera or know someone who hunts and can borrow one, you can see what critter you're dealing with. I bought one last year for $55 from Amazon when I lost my cat and wanted to put a camera on my cat trap. It's pretty cool - takes pictures in the dark and everything.

Jenn