Threats to both species include habitat destruction and predation by non-native cats, dogs, and mongooses, introduced by humans to the solenodons' home islands to control snakes and rodents.

[7] Oligocene North American genera, such as Apternodus, have been suggested as relatives of Solenodon, but the origins of the animal remain obscure.

In 2016, solenodons were confirmed by genetic analysis as belonging to an evolutionary branch that split from the lineage leading to hedgehogs, moles, and shrews before the Cretaceous-Paleogene extinction event.

[8][13] Solenodons resemble very large shrews, and are often compared to them; with extremely elongated cartilaginous snouts, long, naked, scaly tails, hairless feet, and small eyes.

Early studies on the nature of the tiny mammal's saliva suggested that it was very similar to the neurotoxic venom of certain snakes.

More recently, the venom has been found to be related to that of the northern short-tailed shrew and it is mostly composed of kallikreins KLK1, serine proteases that prevent blood clotting, cause hypotension and ultimately end up being fatal to the prey.

The symptoms of a solenodon bite include general depression, breathing difficulty, paralysis, and convulsions; large enough doses have resulted in death in lab studies on mice.

Breeding can take place at any time, with a comparatively low reproductive rate of two litters annually, and males do not participate in the upbringing of their offspring.

Solenodons generate clicking noises similar to those of shews;[20] the sound waves bounce off objects in their vicinity.

This well developed auditory ability combined with its above average sense of smell helps the solenodon survive despite its extremely small eyes and poor vision.

[25] The Cuban solenodon is considered Endangered due to predation by the small Indian mongoose (Urva auropunctata), which was introduced in colonial times to hunt snakes and rats, as well as by feral cats and dogs.

The Hispaniolan solenodon was also once thought to be extinct, more due to its secretive and elusive behavior than to low population numbers.

A 1981 study of the Hispaniolan solenodon in Haiti found that the species was "functionally extinct", with the exception of a small population in the area of Massif de la Hotte.

A follow-up study, in 2007, noted that the solenodon was still thriving in the area, even though the region has had an increase in human population density in recent years.

[26] The Sierra de Bahoruco, a mountain range in the southwest of the Dominican Republic that straddles the border with Haiti, was examined by conservation teams looking for solenodons.

The Durrell Wildlife Conservation Trust and the Ornithological Society of Hispaniola were able to take measurements and DNA from the creature before it was released.

[16] In a 2020 assessment from the IUCN, the Hispaniolan solenodon was found to be much more common on Hispaniola than previously thought, warranting its downlisting from "Endangered" to a "Least Concern" species.

Human development on both Cuba and Hispaniola has resulted in fragmentation and habitat loss, further contributing to the reduction of the solenodon's range and numbers.