Well i can't get any dead fish your to busy eating them all...
Second, they sure could have moved them, third...SO what if the eggs were still there?
Theres been lots of hunts aliens could have done it on one of those, then got killed by other Predators. Third, we don't follow the Aliens every second i'm sure some of them could move it.
And last, where'd you happen to find a map of the Pryamid?