Bat/1.03

Bats are basic fliers. Their best uses are scouting and tower-fodder. =Factions=

Minotaurs
With access to Eagle Eye and Farseeing early on, the Minotaurs Race have no need for scouts, and with tough units across the race that can reliably heal off animals, they don't need to rely on cannon fodder to screen their approach, with only one exception - the Minotaur King. Although they are bulky enough to take considerable punishment, they would prefer not to be in direct line of a tower, especially if you don't have enough of them to raze a base in seconds. While the rest of the Minotaur race may not need a Bat screen to function well, Minotaur Kings can go a long way with them.

Benefits from Training and Eagle Eye researches.

Orcs
Benefits from Training and Eagle Eye researches.

Undead
Undead Bats are unique in the since that in tier 3 you can upgrade them with Vampirism - allowing them to gain HP back upon attacking. However, this doesn't in any way make them useful for combat - it simply allows them to go toe-to-toe with the other bottom-of-the-barrel basic fliers. In other words, Dragonflies. (Opposing non-Undead Bats come from races who have access to the Training skill, effectively giving them 2 extra levels in no-Hero games.) Fighting anything more powerful usually results in the Bat being slain outright. The Undeads' purpose for Bats is scouting and that's basically it - Undead posses better archer / tower fodder in Skeletons (and Cavalry) to absorb physical missiles, or Shadows to sponge elemental attacks. It's rather insulting when you realize that out of all the races that can use Bats, Undead can really only use them for scouts, but yet, Undeads' Bats are the weakest of all other races Bats for that role. This is ironically down to the other races not actually needing them for scouting due to either access to Farseeing or earlier, more useful scouts, but yet they can improve their Bat's scouting role through Eagle Eye.

Benefits from Dark Mithril and Vampire Bats researches.