What is a notable feature of the black widow's venom?

The notable feature of the black widow's venom is that it is a neurotoxin. Neurotoxins are substances that affect the nervous system, and in the case of the black widow spider, the venom can interfere with neurotransmitter function, leading to severe muscle pain, cramps, and other symptoms associated with nervous system disruption. This characteristic sets black widow venom apart from other types of venoms that may cause localized symptoms or general reactions without specifically targeting the nervous system.

Options that suggest swelling, being a sedative, or being harmless do not accurately describe the nature of black widow venom. While some venoms might cause swelling or have sedative effects, the defining feature here is the neurotoxic impact, which specifically targets the nerve cells and can result in more significant health risks than the effects suggested in the other options.