Weird moving pile of insects

Just seen this at a playground in Melbourne Australia. Looks like some sort of caterpillar but they are some how attached to each other and moving. What on earth is going on?

gray cross spider

Maryland. Less than 1/2inch long, found inside.

[Manitoba, Canada] I have never see one of these before. It runs very quickly! What is it?

weird bug / larvae found on ceiling in Aurora Colorado Should i be concerned

What spider is this? Should I kill it or leave it be? it looks to be 1-2inches in size.

From Vermont

Who is this? Seen at 2am during a smoke sesh

Found this while hiking in Colombia

Got bitten twice recently. One healed already but it a nasty bite. Wondering if it was this guy. Can anyone help?

Small white fly/moth with blue/black dots

Just a little guy

From North Carolina. Found this little huybon my car, is just about a inch or less long. Curious what it is.