I carried out a major round-up a a few months ago of the aliens that had been attacking my garden. As you can see they are definitive proof that life from other planets travels here continuously in search of food. For those of you who are astronomers you will notice that each interplanetary specimen wears a shell marker from its own galaxy. I am sure this must be to facilitate sleeping arrangements for the long journeys between planets, (especially if you are travelling at a snail's pace). The Irish railway company, Iarnrod Eireann, are considering a similar scheme so as to avoid the necessity of passengers staying awake in order to have your tickets ready for inspection.
A spokesman for the travellers apologised for any inconvenience they may have caused, but stated that since they had prior occupancy rights on the planet he could not see what all the fuss was about. Snails had after all seeded the sterile planet Earth originally, and any evolutionary problems were down to the impurity of the originally genetically modified seed which was purchased from the Flying F***Company. The company has since gone out of business, and investors were not covered by the Terra Forming Compensation scheme as it was not set up until m6.3412, i.e. after the disaster at Mars.
I did enquire whether there was any chance they might leave all the food to us now, but they said there was no way they were going to leave their investment without getting a decent return! . . . So much for good neighbours!