Battle Bugs
If you donate both the tarantula and scorpion to the museum, they'll attack each other. This is pretty funny as they're in each other's faces.
Also, the tarantula makes the same noise when you shake a tree and the scorpion is similar but the sound is faster. I hope this helps because sometimes it seems to at times you encounter one of them more often than the other. This is the best I can describe their sounds. I'll think of more interesting yet useless information in the future.
More tricks, tips and cheats for this game are right here - Animal Crossing: Wild World cheats
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