Yes, there are vegetarian italian sausages. One example is the Satanic sausage, which is prepared from dough, beans, spices, tomato, yeast, etc. But, yes, majority or I would say almost all of the Italian sausages are non-vegetarian sausages itselves.
I would expect silane because all the rest have an overall dipole movement
Density decreases that's why ice floats on water because it's less dense than water.