Snakes are the least of anyone's worries, they're rarely seen and want to see you less than you want to see them.
However
Midges are a different matter
-and-
-unfortunately-
They can be active pretty much any time of year. Less so at this time of year, although you could be unlucky, but spring to autumn anyone out later in the afternoon/evening is likely to be midge bait.
Make sure you take some midge repellant with you just in case... it may make your retreat back to the car more comfortable than if you'd not taken any
The best midge repellant is "Jungle Formula" with the active constituent "DEET". DEET is a life-saver if a "big wing" of midges comes your way ... but maybe you'd want something a little less like all-out chemical warfare to put on the skin of your children, for them I'd recommend Avon's (yes, that Avon) "Skin So Soft", its not sold as a midge repellant but its widley accepted as having that beneficial effect (for most people), find it here:
Avon's web site
Pour moi its Jungle Juice every time.