In a biomimetic study we compare coconut endocarp material composed mainly of natural cells, calcitic sea urchin spines with cellular character and artificial ceramic material with extreme porosity (Al2O3 from freeze casting and/or ionotropic gelation with 70% porosity) in terms of the change of strength with sample volume. Uniaxial compression and pin indentation were used to determine elastic limits and compression strength. While the truly cellular but low porosity material of the coconut endocarp is clearly obeying Weibull equations for a volume dependence of strength, the sea urchin spines with high porosity do not. In the presentation we compare these results with those from spines of lower and the ceramic materials with higher porosity. We will discuss the behaviour highlighting the boundaries of cellular character, which may limit the volume dependence of strength and formulate conclusions for the up-scaling of such materials from natural role models.