Lugworms!

We often see the characteristic worm casts at low tide on Rosemarkie Beach but this morning they were particularly prominent.

Facts
1. The worms live for 5 to 6 years
2. They stay in the same u shaped burrow sifting the sand for particles of vegetation through their head and casting it onto the beach through the other end.
3. All worms leave their burrow for approx. 2 days over a 2 week period at the end of October for fertilisation of eggs.
4. Could get as many as 100-150 worms in a square metre of beach.
5. They are frightened of dogs.

Which of these facts is/are untrue