Mark Bowler / Three-banded Armadillo (Tolypeutes tricinctus) rolled up in defensive posture. Captive. Endemic to Brazil.

Pete Oxford / Boy sitting on rolls of Balata made from latex collected from Balata / Bullet Wood tree, Nappi, Rupununi, Guyana, used for crafts, February 2010

Petra Wegner / Cavalier King Charles Spaniel, puppy, blenheim coated, aged 10 weeks, curled up on human feet. Model released

Doug Perrine / Salmon shark {Lamna ditropis} captive, with salmon in mouth (eyes are rolled back for protection), Prince William Sound, Alaska, USA, (digitally modified)

Mark Payne-Gill / Brazilian three banded armadillos rolled up in defensive ball {Tolypeutes tricinctus} - head and back view. Articulated tough skin in hinged bands allow flexibility

MYN / Denis Palanque / Pill millipede (Glomeris marginata) rolled up for defence, woodland, Savoie, France, June. meetyourneighbours.net project

Pete Oxford / Long-eared Hedgehog (Hemiechinus auritus) rolled up in defensive posture, Gobi Desert, Mongolia

Piotr Naskrecki / Millipede (Sphaerotherium sp) rolled up in defensive posture, Silaka Nature Reserve, Eastern Cape, South Africa

Piotr Naskrecki / Ball Cockroach (Perisphaerus sp) emerging from rolled up defensive posture, Papua New Guinea. Sequence 4 of 4

Piotr Naskrecki / Ball Cockroach (Perisphaerus sp) emerging from rolled up defensive posture, Papua New Guinea. Sequence 3 of 4

Piotr Naskrecki / Ball Cockroach (Perisphaerus sp) rolled up in defensive posture, Papua New Guinea. Sequence 2 of 4

Piotr Naskrecki / Ball Cockroach (Perisphaerus sp) rolled up in defensive posture, Cambodia