Worm

Not much of a shot I know but when I got to the end of our lane this morning on the way to get the newspaper I came across quite a lot of these little critters sitting on the tarmac in the heat of the sun. What on earth motivates them. I expect they come up in the surrounding woods and then "decide" to go on to the tarmac. But why today? (I guarantee this doesn't happen all the time). This has happened before in previous years about the same time. Perhaps they're all over the place in the woods but you only see the ones that stray onto the tarmac.