The species is found in woodlands dominated by Quercus calliprinos and pine plantations, and in steppe habitats where Asphodelus is predominant.

[1] Harpactea sadistica is the first spider species – and the first member of the entire subphylum Chelicerata – found to use traumatic insemination.

After positioning himself, the male pierces the female on both sides and injects the sperm directly into the ovaries, resulting in about eight holes in two rows.

Consistent with the modified mating behavior, the spermathecae of the female, which normally store received sperm, are weakly developed in this species.

[3] This behavior seems to have evolved in order to ensure that the mating male is also the one providing the sperm for the progeny.