copse snail

For some time I have been envious to mate blippers with the insect- and flyblips.
Since september -08 our weather in northern hemishphere has been hostile to outdoor insects.
This morning I was leaving for shopping and almost fell down in steps because of this snail ( arianta arbustorum) on the lowest step!
Jee, temperature +2 celcius degrees and a snail on my stairs moving ( so it is living) towards the grass, which is under the snow.
The warmer weather globally is here, too, but where did the snail come from?