That is a yellow ratsnake, aka chicken snake . They are probably the most beneficial snake we have. They grow to over seven feet in length & feed primarily on rodents, though they will eat the occasional bird or egg if the opportunity presents itself.

The young are blotched, turning to stripes after a year or so. The youngsters feed on treefrogs. A large adult will wreak havoc on a rat's nest, eating the mother & all the young in one meal.

~~Greg~~
Venomous Snakes of Florida