any trick for killing scarabs and hydras?

[Fluster Zero]

I have 1k of everything else. these 2 just dont spawn until later levels and I went for an hour and a half and got around 100 of both of those... anyone have a strategy for getting these killed?

[Random Dude]

I read somewhere that overkill mode is your best shot at killing all the enemies. Other than that, plain old patience I suppose : S
Btw, could you tell us in what difficulties you got the 5 and 10 million achievements, and what was your strategy?

[Fluster Zero]

if I keep doing overkill mode it will probally take anoher 50 hours to finish this, this achievement is so dumb..

5-10mill i did on easy on my 1st try of easy, i was going on normal since I thought it would be easier to get the score quicker with x5 but only reached 8.5 mill and hard made it to almost 5 mill after a few gos. it takes around an hour-hour and a half to get 10mill in easy

[montrossity]

I also need a lot more scarabs and hydras along with guardians. It just doesn't seem like scarabs and hydras ever spawn.