Why did Moshe compare their defeat at the hands of the 'Emori' to an attack of bees?
Rashi: Because, like bees (which die after they have stung), the moment an 'Emori' struck a Yisrael, he died. 1
Hadar Zekenim #1 and Riva: When one bee leaves the bee-hive, all the others follow. Likewise, when the Amaleki came out to attack Yisrael, the Cana'ani came out with them, as the Torah relates in Sh'lach-L'cha, Bamidbar 14:45 "va'Yered ha'Amaleki ve'ha'Cana'ani".
Hadar Zekenim #2, Da'as Zekenim and Rosh: Like bees, which sting in various parts of the body, but do not kill, they struck and chased them, but did not kill them. 2
Ibn Ezra: If anyone touches their hive, they chase him and sting him.
Alshich: They made a big noise and chased Yisrael without swords, just like bees buzz and people flee to avoid being stung. And after they fled, they struck them.
Oznayim la'Torah: As opposed to the owner, who smokes out the bees before taking their honey, a thief, who is afraid to smoke the hive for fear of getting caught, tries to steal the honey directly and ends up getting stung and is forced to flee for his life. In similar vein, if Yisrael had entered the land as owners - as Hashem commanded "Alei Reish!" - the Pillar of Cloud and the Badei ha'Aron 3 would have 'smoked out' the Cana'anim, who would have fled, and Yisrael would have taken ownership of the land; but now that they tried 'to steal' into Eretz Cana'an, they lost Divine protection, and were defeated and forced to flee.
Refer to 1:44:152:1-3. The reason that Hashem performed that miracle was in order to counter the spies, who claimed that the Cana'anim were invincible - See Oznayim la'Torah - or to console Yisrael who were extremely depressed following the decree that they would not enter Eretz Cana'an.
Hadar Zekenim #2, Da'as Zekenim and Rosh: To prevent them from bragging and creating a Chilul Hashem. Proof of this lies in the fact that the Torah does not say how many died here, like it says in other places. In similar vein, the Torah wrote in Chukas Bamidbar, 21:1 "va'Yishma ha'Cana'ani Melech Arad? va'Yishb mimenu Shevi", implying that they did not kill anyone.
See Oznayim la'Torah.
Here the Torah writes that the Emori struck and chased Yisrael until Chormah, However in Chukas Bamidbar, 21:3 it states that Yisrael defeated the Cana'anim, and called the place Chormah?
Hadar Zekenim: There were two wars in Chormah.
Here the Torah writes that the Emori struck the Mapilim, whereas in Sh'lach-L'cha Bamidbar, 14:45, it says that the Amaleki and the Cana'ani struck them?
Ibn Ezra: 'The Emori is synonymous with the Cana'ani, as I explained' in Sh'lach-L'cha Bamidbar, 14:25.
The Amaleki and the Cana'ani came to help the Emori. Refer to 1:44:1:2.
Malbim: The Amaleki and the Cana'ani were in the valley and the mountain. The latter were called Emori - since they ruled that area. They struck Yisrael, and the Amaleki and the Cana'ani in the valley did not need to, for they saw that Yisrael were defeated.
