I have tried just about every bait there is including peanut butter but after one squirrel is caught it is like he sends out a signal to all the others and they usually won't fall for it again. These are city slicker squirrels. My neighbor used traps for 3 years and only got two squirrels using every bait he could think of. I still can't believe they wouldn't fall for the shelled pecans and peanuts. They won't touch rat poison even when it is placed in the trees near their favorite perches. I used to think rats were worse but at least you could thin them out quickly with poison and I don't care how inhumane it is. At this point I would water board them before poisoning them.
Rats are disgusting, disease carrying vermin and city squirrels are getting almost as bad living and breeding in peoples attics and outbuildings.
I actually had them chew right through the asphalt shingles on my roof about 6 years ago in two different places to get into my attic. They nearly caused one of my neighbors houses to catch fire from chewing on the wiring running through her attic. I now have a metal roof and hardware cloth protecting all my attic vents and had most of the lower limbs on all my trees trimmed off to limit their access to my house. My next door neighbor just gave up and had all his trees removed because of the aggravation they constantly were causing them. They keep chewing through our cable lines causing loss of tv and internet until a line can be replaced. They have actually become a plague in this part of town and the city linemen and cable people hate them because of how many lines they destroy yet the city government won't allow them to kill squirrels. They are so cute.
I never cared if critters took a bit of my gardening bounty but a few years ago they got too plentiful and have been taking their share and a lot of mine and sometimes all of mine.
Bill