Bubble Witch Saga 2 Bugs or the small Spiders that appear when playing are used to increase you score so you can get 3 stars. On most stages these little guys are going to be the only way to complete it 100% so knowing how to increase their numbers is essential for victory.
To get more of them on the board you need to make small combos of bubbles and after you feel there is enough your gonna want to drop a bunch of bubbles to rack up your score. Keep in mind that if you make a move and fail to make a combination all of your bugs or spiders will disappear making it a little tricky sometimes.
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You have the best chance if you try to look ahead a few moves so you can maximize the bug count and hopefully get 3 stars. This is not always an easy thing though as every board is random as far as orb colors and positions though some stages will always be the same with a little bit of variation.
If you get enough of them you will almost create a barrier where orbs seem to bounce forever back and forth between each other giving you instant 3 stars with a bunch of extra.
All matches whether big or small will create 1 spider.
All will disappear completely if you do not make a match.
They are the color of the combo you made.
Don’t focus to much of raising the count of your insect friends as you might not have enough moves to complete the mission.
The absolute best time to drop a big load on a group of unsuspecting insects is to do so when you have a Hot Pot which will sent your points through the roof. Hot Pots can be trigger by making multiple matches in a row and will stay around for a limited number of shots.