Instruction: Answer the given question by extracting information from the supporting document.

Input:
Question: does it attach to ceiling/eave or wall , or either?
Document: These are just OK for their intended use. There is no way to snug the unit up to the wall or ceiling. This leaves a gap, which is a telltale sign it is a fake.You need to put the screws into the wall/ceiling, and the twist the unit a few degrees to move the screws along the slot. If you have any vibration, the unit will probably fall. I had to push some foam in between the unit and the ceiling to keep it from vibrating loose. They put all the money into the springs, and an on-off switch activated by pushing the dome, and they should have come up with a better mounting system (even the twist-lok like smoke alarms would be OK)As far as motion sensing, the LED blinks all the time.
Product I received looks very similar to the picture shown in current description. Black base has 4-1/2 inch diameter, total base/dome height is 3 inches. All-plastic construction, with small simulated camera lens and nearby red-flashing 'activation' LED. Black inner dome, shields back of 'camera' from view. Aim is fixed at about a 45 degree angle, so need to point in the general direction when hanging. Base has 2 opposing screw-slots to mount on wall/ceiling with a slight twist, so proper aiming takes a bit of planning (2 screws and optional plastic-anchors are included).Unlike the description photo, my red LED is located on the base-side of the camera lens (instead of top-of-dome side as pictured).
Perfect for price, great alone to add with existing and real cameras. Works either way. Looks good, packaged well, way good price.\
Although advertised with a motion sensor (even on the box), the wires from the batteries go straight to the LED. It has springs, but they don't turn it on as off as suggested either. Based on the real specs, it is very overpriced
I'll put them up so high on the wall (19ft) that people will simply ignore them. Oh well...
I put this high on the wall outside my carport door. It would be more convincing with dummy wires attached as described in another review. It was so easy to install, and the blinking red light, on a motion sensor, makes you take notice.
This is pretty convincing as ceiling mounted cameras go, was an easy install. It arrived sooner than I expected it to.
The Dummy dome camera with flashing red light looks very realistic, and is highly visible. A very inexpensive and effective deterrent. The only drawback is the problematic battery exchange. You have to take the device apart, and unscrew it from the wall, to get to the battery compartment.
Yes, when placed on the ceiling of our youthroom in a strip mall,  they look quite authentic.... very pleasedwith the overall effect, especially at night...
Product is very cheaply made. Had to solder the wires back on as they came off when opening to mount on ceiling. Does have a realistic look once it's up. For the price, what the hey!
Answer: yes there are two screw holes on the back , just like a smoke alarm - i used heavy duty velcro to place then on the wall and they work great - it depends on the surface  ,but screws are the safest bet