A loud scree and sound of multiple sharp limbs furiously tapping at the thick and clear barrier around itself is all that the small facehugger could do. It could sense something in the vent, although not very clear, but something is that dark vent. Tapping its limbs against the window much faster, the small facehugger moves around in the containment. Its acidic blood drip down to the base of the containment, creating sizzling noise. But all of those is not enough to puncture through the somewhat thick containment.