There are eighteen different types of enemies/creatures (colloquially called “mobs”) in Bee Swarm Simulator.
Other than ants, the most frequently occurring mob is the rhino beetle as there are five of them in the game. The least frequently occurring mob is the Stump Snail, respawning in 96 hours (4 days) or 81 hours and 36 minutes (if you have a Gifted Vicious Bee) upon defeat.
You can't fight the mobs yourself; only your bees can. One method for defeating mobs that reliably works for any mob that defends a field (everything other than the King Beetle, Tunnel Bear, ants, the cave monsters, Stick Bug, Rogue Vicious Bee, Wild Windy Bee), with the exception of the Coconut Crab is to jump continuously. It is one of the Glitches where when jumping, mobs will freeze and not attack which leads to your bees thinking the mob isn't a threat and not attack it. You do have to make sure your bees "know" to attack a mob before starting to jump - if the mob hasn't started attacking you, your bees might not recognize it as a threat. However, this method does not affect the Stump Snail or the Coconut Crab.
Before the 2/1/2019 update, rewards from defeating any mob was sent to the player's inventory right when the mob is killed. After the update, the mobs drop a ring of tokens around it instead (battle points don't spawn as a token). Other players can't steal tokens dropped by the mob if the mob isn't spawned by them. The tokens can be collected by a Token Link token.
Mobs have levels that are shown next to their name. If your bees are a lower level than the mob they're attacking, they have a chance at missing their attacks but sometimes they still attack.
While some mobs are considered Bosses, others do not qualify for this designation. These mobs are called Mini-Bosses, distinct from regular mobs but not qualifying as a boss. Wild Windy Bee, Rogue Vicious Bee, and Stump Snail are all in this category.
Daylight Saving Time will affect the respawn time of the Stump Snail, King Beetle, and Tunnel Bear.
Using Baby Love before defeating mobs and bosses tends to give better rewards.