Most microbats, especially in temperate areas, prey on insects.<ref name="Feton104" /> The diet of an insectivorous bat may span a wide range of species,<ref>Feton and Simmons, pp. 108–10</ref> including [[flies]], [[beetle]]s, moths, [[grasshopper]]s, [[cricket]]s, [[termite]]s, [[bee]]s, [[wasp]]s, [[mayflies]] and [[caddisflies]].<ref name="MacDonald">{{Cite book |author=Jones, G. |contribution=Bats |year=2001 |title=The Encyclopedia of Mammals |edition=2nd |editor=MacDonald, D. |publisher=Oxford University Press |pages=754–75 |isbn=978-0-7607-1969-5}}</ref> Large numbers of Mexican free-tailed bats (''Tadarida brasiliensis'') fly hundreds of meters above the ground in central Texas to feed on migrating moths.<ref>{{cite journal |pmid=21669777 |year=2008 |author1=McCracken |first1=G. F. |title=Brazilian free-tailed bats (Tadarida brasiliensis: Molossidae, Chiroptera) at high altitude: Links to migratory insect populations |journal=Integrative and Comparative Biology |volume=48 |issue=1 |pages=107–18 |last2=Gillam |first2=E. H. |last3=Westbrook |first3=J. K.|last4=Lee|first4=Y. F. |last5=Jensen |first5=M. L. |last6=Balsley |first6=B. B. |doi=10.1093/icb/icn033}}</ref> Species that hunt insects in flight, like the [[little brown bat]] (''Myotis lucifugus''), may catch an insect in mid-air with its mouth, and eat it in the air or use their tail membranes or wings to scoop up the insect and carry it to the mouth.<ref>{{cite web |title=Little Brown Bat |publisher=Penn State University |url=http://www.psu.edu/dept/nkbiology/naturetrail/speciespages/little_brown_bat.html|accessdate=2017-09-13}}</ref><ref>Feton and Simmons, 120</ref> The bat may also take the insect back to its roost and eat it there.<ref>{{cite journal | last1=Fitt | first1=G. P. | year=1989 | title=The ecology of Heliothis species in relation to agro-ecosystems | journal=Annual Review of Entomology | volume=34 | issue=| pages=17–52 | doi=10.1146/annurev.ento.34.1.17}}</ref> Slower moving bat species such as the [[brown long-eared bat]] (''Plecotus auritus'') and many horseshoe bat species, may take or glean insects from vegatation or hunt them from perches.<ref name="MacDonald"/> Insectivorous bats living at high latitudes have to consume prey with higher energetic value than tropical bats.<ref>{{cite journal|last=Boyles |first=J. G. |last2=McGuire |first2=L. P. |last3=Boyles |first3=E. |last4=Reimer |first4=J. P. |last5=Brooks |first5=C. A. |last6=Rutherford |first6=R. W. |last7=Rutherford|first7=T. A. |last8=Whitaker |first8=J. O., Jr.|last9=McCracken |first9=G. F. |year=2016 |title=Physiological and behavioral adaptations in bats living at high latitudes |journal=Physiology and Behavior |volume=165 |pages=322–327 |doi=10.1016/j.physbeh.2016.08.016}}</ref> Even though insects serve as an important source of nutrition for bats, certain lepidoptera species such as [[''Ostrinia Scapulalis''scapulalis]] can emit ultrasonic pulses to confuse and fend off bats.