We could tie Pastel back in and say that to test if you have a homozygous (super) pastel OR a homozygous spider you could breed it to normals and see if you produce all morph (either pastel or spider) babies. Technically you could never be absolutely sure you weren’t just very lucky and produced all morphs with a het but the odds against that get longer and longer the more babies you produce. For example, the odds of going 6 for 6 on baby pastels or spiders with a het X normal breeding is only about 1.6% (1:64). The odds of going 10 for 10 is about 0.01% (1:1,024). The odds of 20 in a row is 0.0001% (1:1,048,576). So, if your spider produces 20 spiders and no normals in it's first 20 eggs bred to normals is it "proven" homozygous spider or where you just 1 in 1 million lucky?