can eject: if size >= 60 i.e. mass >= 35 
eject makes me lose 16 mass
eject distance is between (600+my.size) and (700+my.size), about 10-15 deg deviation
can eat ejected mass if mass >= 18 i.e. size >= 43

cell can eat us, if their size/mass(??) is at least 1.25* our size/mass

zoom level is 369.399 * sum(own_cells.size) ** 0.431776