Cimicids are a specialised group of blood-sucking parasites that primarily feed on bats, birds and humans.
They are thought to have evolved from predatory heteropteran ancestors, with about 60% of extant species using bats as their primary hosts.
Bats are social mammals and many species congregate in communal roosts to give birth and rear their young.
These roosts provide excellent conditions for their arthropod ectoparasites, with a steady temperature and opportunities for regular blood meals.
However, the bats frequently groom themselves and each other, putting the parasites at risk of being eaten.
Cimicids lessen this risk by hiding in concealed locations between feeding bouts, and by producing a repellent substance which makes them distasteful.

In evolutionary terms, most species of cimicid probably specialised on insectivorous bats or birds, with the possibility of dispersal to other sites via their winged hosts.
On returning to a roost, a bat may only be available to cimicids for a short time before it cools down and enters a state of torpor, with reduced blood flow.
When the bats lived in close proximity to humans, in caves or in the roofs of their huts, a new opportunity arose; the cimicids could make use of the large size and homeothermic properties of a human, which provided an abundant food supply that led to the growth and expansion of the ectoparasite populations.

Cimicids are relatively specialized in their choice of hosts, compared to other bloodsucking insects.
Most cimicids have a preferred host, but accept some others when presented with the choice, such as C. lectularius and C. hemipterus, which are most often found among humans, but can also survive by feeding on birds, bats, rabbits, and mice.
The subfamilies Primicimicinae and Latrocimicinae use New World bats as their hosts, while Afrocimicinae and Cacodminae use Old World bats.
Bats represent a convenient mammal to exploit as they roost communally, returning to the same roost regularly.
It is perhaps to avoid the parasites that some species of bat regularly change roosts.
The subfamily Haematosiphoninae use birds in the swift and swallow families, Apodidae and Hirundinidae.
One species, P. cavernis, has a very limited distribution and appears to make use of only one species of host.

Host switching is dependent on several factors, including overlap in host detection cues and ability to digest different kinds of blood.
For example, the red blood cells of chickens are about 3 to 5 μm longer in diameter than those of humans, making human blood more suitable for the narrow food canal of C. lectularius.
C. hemipterus may be able to vary the size of its food canal, allowing it greater flexibility in its choice of hosts.
Preference for a host species can vary between populations of a given species; the causes for this are unclear.
Cimicids are a specialised group of blood-sucking parasites that primarily feed on bats, birds and humans. They are thought to have evolved from predatory heteropteran ancestors, with about 60% of extant species using bats as their primary hosts. Bats are social mammals and many species congregate in communal roosts to give birth and rear their young. These roosts provide excellent conditions for their arthropod ectoparasites, with a steady temperature and opportunities for regular blood meals. However, the bats frequently groom themselves and each other, putting the parasites at risk of being eaten. Cimicids lessen this risk by hiding in concealed locations between feeding bouts, and by producing a repellent substance which makes them distasteful.
In evolutionary terms, most species of cimicid probably specialised on insectivorous bats or birds, with the possibility of dispersal to other sites via their winged hosts. On returning to a roost, a bat may only be available to cimicids for a short time before it cools down and enters a state of torpor, with reduced blood flow. When the bats lived in close proximity to humans, in caves or in the roofs of their huts, a new opportunity arose; the cimicids could make use of the large size and homeothermic properties of a human, which provided an abundant food supply that led to the growth and expansion of the ectoparasite populations.
Cimicids are relatively specialized in their choice of hosts, compared to other bloodsucking insects. Most cimicids have a preferred host, but accept some others when presented with the choice, such as C. lectularius and C. hemipterus, which are most often found among humans, but can also survive by feeding on birds, bats, rabbits, and mice. The subfamilies Primicimicinae and Latrocimicinae use New World bats as their hosts, while Afrocimicinae and Cacodminae use Old World bats. Bats represent a convenient mammal to exploit as they roost communally, returning to the same roost regularly. It is perhaps to avoid the parasites that some species of bat regularly change roosts. The subfamily Haematosiphoninae use birds in the swift and swallow families, Apodidae and Hirundinidae. One species, P. cavernis, has a very limited distribution and appears to make use of only one species of host.
Host switching is dependent on several factors, including overlap in host detection cues and ability to digest different kinds of blood. For example, the red blood cells of chickens are about 3 to 5 μm longer in diameter than those of humans, making human blood more suitable for the narrow food canal of C. lectularius. C. hemipterus may be able to vary the size of its food canal, allowing it greater flexibility in its choice of hosts. Preference for a host species can vary between populations of a given species; the causes for this are unclear.
Cimicidae