There's been a lot of shaking in Oklahoma in the past few days.
Seismologists at the Oklahoma Geological Survey say in the last 24 hours, there have been been over a hundred quakes.
Most aren't strong enough to feel.
One neighborhood in Guthrie had nearly three dozen quakes---centered in one location.
Now residents there are wondering if a hydraulic well just a half mile away has anything to do with the shaking.
Penny Murphy--whose house sits on the epicenter of one of the quakes---says she's a little uneasy.
"It's too close for comfort," she says.
She's lived just outside Guthrie for 22 years, and just recently started feeling the phenomenon.
"Last weekend, we had one big boom, where my husband thought someone actually hit the house or something, that was the first time we really had a big one until this weekend," Murphy said.
Murphy says this weekend's quakes were a first. Her house sits in the center of about 30 medium-sized quakes that hit, all in this neighborhood.
45 miles to the south at the Oklahoma Geological Survey, Austin Holland says you can blame both man and nature for the recent quakes.
"There's probably a combination of different factors going on, there's probably some earthquakes being caused by man's activities, and some that are being caused by natural processes within the earth," Holland said.
He says this area has a fault nearby, so it's not a total surprise there are quakes here.
"Most of it is the earth doing its thing, and what man does is influence the timing of those things," Holland said.
Stresses in the earth's crust are already built up, Holland explains. When drilling happens, it just releases the stress earlier than it would've happened naturally.
Penny Murphy says she's a hearty Oklahoman: she's been through fires, floods, tornadoes and now earthquakes.
"You live where you live and you have to take the elements with it. I just never thought in Oklahoma an earthquake would be added to that," she said.