They’re helping you, not hurting you.” Editor’s note: This article was updated at 5:35 p.m. Friday, Nov. 17, 2023, to correct that the red hourglass shape is on black widow spider’s abdomens.

Black widow spiders are being killed off in the U.S. The culprits are actually their cousins: brown widow spiders. Though the reason behind the killings is unknown, a new study suggests.

Black widow spiders are being killed off in the U.S. The culprits are actually their cousins: brown widow spiders. Though the reason behind the killings is unknown, a new study suggests.