The way that I interpreted the Crashes were that they were exploding to protect their nest, not themselves. This would still suggest some kind of alternative behavior for 'juveniles' as every single crash nest you find can't be housing an adult with…
I would offer a heavy 'second' to the vertical ladder tubes. I would also amend that suggestion by saying that the ladders should be able to 'transform', so to speak, into a single ladder that when used simply puts you on the next available level up…